Top Posts Tagged with #shark!hybrid

ETHOGRAM ENTRY VII — ??????: Merfolklore, Saltblood and the Becoming.

The first thing Sukuna notices is that you stop wasting energy on anger.

You still snap at him sometimes, still roll your eyes when he calls you soft, still mutter sharp little corrections when he pretends he doesn’t know what he’s doing to you. But the edge is dulled by exhaustion, the way a blade dulls when you keep using it on stone instead of meat. You don’t pick fights you can’t afford anymore, you don’t climb the ridge every other day to stare at the horizon and come back with your face pinched tight, cheeks sunburnt and lips split, you sit more, you lie down more, you move like every action requires a decision first.

He hates that he can tell before you even speak.

You spend longer by the fire, knees hugged to your chest, staring into the coals like they might rearrange into a solution for all your problems. When you stand, you do it slower. When you walk, you brace your palm to rock sometimes, as if your balance is something you have to borrow from the island. Your appetite turns fickle — you pick at fish he brings like it’s a chore, you chew because he watches you chew.

He doesn’t understand humans the way he understands currents, but he understands prey and sickness and the thin line between them. In the facility, you had a steady smell. Annoying soap, clean cloth, the sterile tang of metal and filter systems stuck in your hair. Out here, you smell like salt and smoke and sweat, and under it there’s a faint sharpness that wasn’t there before — an edge he keeps catching when the wind shifts and you turn your head.

Not rot, also not infection.

Not yet.

Something else.

It bothers him because he can’t categorize it quickly, and he is not patient when something near him changes without his permission.

You wake up the next morning with your hands pressed to your lower belly, face tight with pain. Your breath is shallow. The expression on you is the one he’s learned means you’re trying not to make noise because you think noise will make you weak. He’s in the shallows, half risen on the rock shelf, and the moment he sees you he’s already moving closer, claws scraping stone.

“Up.” he orders, because ordering is what he does when he doesn’t know what else to do.

You blink at him, slow, eyelids heavy.

“I am up.”

“You are folded,” he corrects, and his eyes rake you like he’s scanning for wounds. “What.”

You swallow, press your forehead briefly to your knees, and the scent hits him sharper — copper, faint but undeniable, threaded through your skin like a hook.

His pupils widen without permission.

That smell still flips something old in him, because he didn’t get used to it yet.

It pulls the predator tight, makes his attention narrow until the rest of the world turns into background noise. His eyes are trained on you, wild blown pupils, taking you in as if preparing to attack.

You go still, eyes on his face.

He hates the way you do that — freeze and wait, as if he’s the only thing that can decide what happens next.

It should satisfy him.

It does, in a way that makes him feel uglier than he wants to admit.

“You still bleed.” he says, low. “And still hide the pain.”

“I know,” you answer, voice strained. “I’m still not dying, don’t worry.”

He inhales again, longer this time, and the copper threads into his head like hunger made of smell. His jaw tightens.

“You smell like it.” he says, as if accusing you of doing it on purpose.

You manage a rough laugh that turns into a wince.

You shift, trying to sit up straighter, and the pain spikes across your face again.

Sukuna sees it. He reaches out and — as usual — grabs your ankle to pull you closer to him. And you barely writhe, letting him close the distance, letting him drag you until your legs are almost in the water.

His hand clamps on your hipbone once you’re splayed under his looming form, steadying you, thumb pressing absent circles like he can rub the hurt out of your body through force alone.

“You are weaker.” he mutters.

You glare at him with what little energy you have.

“I’ll be fine,” you manage, and it’s the same lie you always give him when you don’t want him to see you struggle.

Sukuna doesn’t believe you — he watches your mouth move around the words, watches the way your shoulders slump afterward like you’re already tired from talking.

He doesn’t leave you alone that day.

He stays close to the shore while you try to pretend you can do your normal routine — clean fish, tend the fire, check the rock pools for anything drinkable, gather damp wood that might someday dry. You move slower and he moves with you, in the water, matching your pace without looking like he is.

When you crouch too long and then stand too fast, you sway. Sukuna’s hand catches your calf immediately, claws careful, holding you steady until your vision clears.

He doesn’t comment, he just refuses to let you fall.

When you finally sit again, breathing hard, you don’t meet his eyes.

He leans nearer, upper body braced on stone, tattoos dark and sharp against wet skin. His pupils are still too wide. The copper scent keeps tugging at him in small, relentless pulls, and he hates it because he can’t decide whether it’s hunger or something else.

“You need your pills.” he says, curt, as if stating the obvious will make it stop being a problem.

“No.”

“You need them.” he repeats with a sneer.

“I needed them to keep the lab quiet,” you correct, and the bitterness in your voice makes his jaw tighten. “Out here I need… food. Water. Rest. A bed that isn’t rock.”

He watches your face for a moment.

“You have me.”

You laugh again, small and tired.

“You’re not a bed, Sukuna.”

His mouth twitches.

“I am warmer than rock.”

You don’t answer that, because it’s true and you don’t want to admit how often you’ve used his body heat to keep from shaking at night.

Days pass. Weeks even.

Your bleeding comes and goes.

The smell fades, and with it the sharp predator hunger eases.

Sukuna still stays close, though, like the scent woke something in him that won’t go back to sleep.

The worse part isn’t the period.

It’s everything stacked on top of it.

The sun keeps burning you. You try to cover your skin with wet cloth, try to stay in shade, but shade is limited and the island doesn’t care about your comfort. Storms dump rain so hard it flattens your fire and leaves you shivering under overhangs, clothes clinging cold and heavy. The next day the heat returns, and the salt on your skin turns into a crust that cracks when you move.

You eat, but not enough. You drink rainwater when you can catch it, but you can’t force rain to come when you’re thirsty. Your lips split, your hands crack, your nails break. You stop laughing entirely for a stretch of days, and Sukuna starts staring at you like you’re doing something wrong on purpose.

He brings you fish bigger than usual, fattier. He brings you shellfish once, prying them from rock with claws and dropping them at your feet like he expects you to know what to do. You boil them in seawater because you can’t risk eating them raw.

You chew and swallow and still feel hollow.

You sleep more. When you wake, your muscles ache like you’ve been fighting even though you’ve done nothing but survive.

The changes start quietly enough that you almost miss them.

Sukuna doesn’t miss anything.

He notices the way your breath behaves in the water first.

You’ve always been decent at diving — trained lungs, practiced control — but now, when you wade into the shallows to rinse cloth or cool your skin, you hold your breath longer without thinking about it.

Your body doesn’t panic as quickly when a wave slaps your face.

You come up calmer, eyes clearer.

He sees you cough less after being submerged.

He sees you stop shivering as violently when the water is cold.

It’s not dramatic, not sudden, but it’s there.

Then he notices you start craving salt like it’s food.

You lick it off your lips.

You chew dried seaweed without making a face.

You even sprinkle sand-rinsed salt from a shallow pool onto fish like you’re seasoning it, and when he asks why you’re doing that, you shrug and say your body wants it.

Sukuna watches you swallow, eyes narrowed.

He remembers how you tasted in the facility — clean, human, controlled.

He remembers how your body smelled when you stopped pretending you weren’t attached to him.

He remembers the two times you let him take what he wanted, how he filled you up with his eggs and his seed, the way you clung to him like you were trying to absorb warmth through skin. You tasted different the second time, and it wasn’t the blood.

He remembers the tunnel, too — the way he pressed his mouth to yours and forced breath into you because you were stupid enough to come with him.

He doesn’t like thinking about it because it means he can’t claim you’re just an inconvenience anymore.

Saltblood.

It has been inside you for a while.

He knows that, even if he’s never said it out loud.

It lives in merfolk the way the ocean lives in the cracks of rock, persistent, invasive, necessary.

It transfers in small ways — mucus, blood, saliva, sex.

It’s been part of him for so long that he doesn’t separate it from himself, he can’t — no current generation of merfolk can.

Human life seemed simpler for you — warm rooms, food that doesn’t have to be fought for, medicine, soft beds, paper maps.

You didn’t present any change after he claimed you as his own back in the facility, any transformation, any discomfort that could mean transmission and incubation. Nothing. You were still you, entirely.

He told himself you would be happier with those human things, in your human life, so he didn’t push your luck.

But you chose to come with him, you chose him, and that would be your demise.

Now he watches you grow thinner in the sun and realizes how stupid that assumption is.

You sit by the fire one evening, shoulders slumped, face turned toward the coals. The sky is clear for once, stars starting to sharpen overhead. You look like you should be resting, but you’re tense as if you can’t relax even when you stop moving.

Sukuna is in the shallows again, half risen on the rock shelf, his tail drifting slow behind him. He watches you pick at fish with unsteady hands, and something in his chest tightens with irritation he can’t place.

“Eat.” he says.

“I am.” you answer, and the lie is weak.

He pushes higher onto the rock, water streaming off him. His hand clamps around your wrist and stills it.

“You are getting smaller.” he says, blunt.

You blink at him like it’s effort.

“Good observation.”

He tightens his grip, annoyed by your sarcasm.

“You’re dying.”

“I noticed.” you say, flat.

His eyes narrow and his upper lips rise in a snarl.

“Stop acting like you do not care.”

You stare at the fire for a long moment. When you speak again, your voice is quieter.

“I care, Sukuna.” you admit. “I’m just… tired.”

The words make something in him go still.

Tired is what prey says before it lies down and doesn’t get up again.

He releases your wrist and hooks his fingers under your chin, forcing you to look at him. His claws don’t cut you, not even a scratch. He’s careful with you in ways that disgust him because they feel like softness.

“Say it.” he orders.

Your eyes flick over his face, pupils too wide, red rims thin. You swallow the tightness in your throat.

“I don’t think I’m going to live much longer…” you say in a murmur, and you say it like a fact. Like you’re giving him a lab report you don’t want to write.

The world inside him shifts.

He’s been alone most of his life, and loneliness never scared him. It was clean. It was simple. No one to lose. No one’s body to carry in memory.

You ruined that. You still do.

The idea of you leaving — of you dying — hits him in a place he doesn’t like to acknowledge. It feels like something sharp pressing under his ribs gutting him open. It makes him want to grab you hard enough to bruise and shake you until you take the words back.

Instead, he stares at you. His jaw clenches and he grits his teeth. His grip on your chin tightens a fraction.

“You talk like prey.” he growls, voice low.

You don’t flinch.

“I’m being honest.”

He hates honesty when it isn’t useful.

“You are stubborn,” he chides. “You survived the tunnel. You survived storms. You survived me.”

You give a faint, exhausted smile that makes him tilt his head just slightly.

“That’s a strange motivational speech.”

He bares teeth wider, violence is how he’s used to solve his issues.

“Do not mock.”

You swallow again, then shrug weakly.

“What do you want me to say? I’m hungry all the time… I’m cold even when it’s hot. My head spins when I stand. I can’t remember the last time I felt… normal.”

Normal. A human word for comfort and predictability.

He releases your chin with a rough shove, then immediately regrets it when your head dips like you’re too heavy to hold up.

He catches you by the shoulder and steadies you again, breathing out hard through his nose.

His gaze drags over you — sunburnt skin, split lips, bruises on your knees from rock, the way your collarbones stand out sharper than they should.

He’s seen humans starve before, get taken by illness and exhaustion too.

He knows what death looks like.

He also knows you smell different.

Not only weak.

Not only human.

Saltblood is threading through you, and it’s doing it faster now because you don’t have your clean food and your medicine and your controlled sleep. You don’t have your immune system working properly to suppress it.

Your body is stressed and cracked open, and the symbiont, much like a virus, takes advantage like it always does. It doesn’t care about your human plans. It cares about survival in the sea.

He should feel satisfied with that thought.

He feels furious instead.

Because if you change, you might live — but you might not be you anymore.

And if you die, you’ll be gone, and he will be left with the ocean and the memory of your voice in a glass house.

He hates both options.

He stands back, half in the water, forearms braced on the rock shelf. His shoulders look tense, his posture tight, like he’s restraining himself from doing something violent.

“You want to live.” he rasps, and it sounds like a demand instead of a question.

You blink slowly.

“Yes.”

“Good.” His eyes narrow again, sharp. “Then you will.”

You snort softly, not even amused.

“That’s not how it works.”

Sukuna’s mouth curls.

“It is how it works for me.”

You look at him, and in the firelight your face softens in a way it rarely does anymore.

“We aren’t the same.”

He holds your gaze.

“Would you want to be?”

The question hangs between you like a current shift — subtle, but it changes everything.

You inhale, and the air catches in your chest like it hurts. You let it out slowly.

“If I could live in the sea without… suffering,” you say quietly, “it would be a dream.”

Sukuna goes still.

Dream.

Another human word.

You say it like you mean it, like the sea has always been your home in your head even when your body couldn’t claim it.

He remembers you in the facility, talking through the glass about wonders you wanted to see, about diving not for study but for joy. He remembers how you looked when he first took you into the water and you didn’t fight him, only trembled and stared like the ocean was a god you wanted to meet.

He didn’t understand then.

He understands now.

“You would leave your land.” he states, voice low.

“I don’t have land,” you answer, and there’s no bitterness in it this time. Just exhaustion. “I have rocks and storms and your fish.”

His eyebrows furrow and he reminds you.

“You have me.”

You look at him, and the silence that follows is too thick with things neither of you says.

He breaks it first, because he can’t stand the softness of it.

“There is a way.” he says, blunt.

You blink.

“What?”

He watches your face carefully, and it irritates him how much he cares what you do with his words.

“Salthblood,” he says. “It can take you. It already is.”

Your mouth parts, surprise and fear mixing.

“I— I thought that was just… folklore. A story you told to scare me out of stupid ideas.”

His lips curl and his pupils thin.

“You think my world is stories.”

“No,” you correct quickly, then stop and swallow. “I just didn’t know it could— happen to me.”

“It happens when the sea wants you.” he huffs, and he hates how close that sounds to something mystical.

He prefers facts, but merfolk biology is old and strange and layered with ritual because it kept them alive when humans were still learning to float.

You glance down at your hands, cracked and raw.

“If it takes me… do I become— what. Like you?”

Sukuna’s eyes flick over you with possessive assessment.

“Not like me.”

“What then?” and your eyebrows furrow with a little bit of concern.

He thinks, jaw tight.

Seal is what makes sense.

It fits the way your body is leaning — endurance, warmth, amphibious comfort, land and sea.

It’s a shape that survives cold currents and long swims, that holds breath and returns to the surface without panic.

It’s also prey-coded, which is an ugly thought that makes him feel satisfied in ways he doesn’t want to admit.

“Seal,” he says finally. “Or something close. Soft. Built for long water.”

You glare weakly.

“Soft.”

He bares teeth.

“You are soft. You will remain soft.”

Your laugh is faint, but it’s real, and it surprises both of you.

Then you sway slightly, fatigue catching you mid-breath, and Sukuna’s hand shoots out to steady you again, grip firm on your upper arm.

His pupils flare wider.

He makes a decision with the same brutal finality he makes all decisions.

He’s not going to let you die on a rock.

He’s not going to gamble on saltblood taking you on its own timeline.

He’s going to force the sea to keep you.

He looks out at the dark water beyond the cove, beyond the island, beyond the places he’s shown you.

There are merfolk who know the symbiont the way he knows teeth and hunt and violence.

There are merfolk who treat saltblood like craft, like heritage.

Ones who can guide a becoming without tearing a human apart in the process.

He knows one in particular.

Suguru.

Half giant octopus, half human, he suspects — too clever for his own good. A merfolk who collects knowledge the way Sukuna collects scars. Suguru understands saltblood not only in the body but in the culture — how to make the change survivable, how to make it accepted, how to stop it from becoming a death sentence or a curse.

Sukuna looks back at you.

You’re watching him, eyes heavy, trying to read his face.

You can’t. Humans never can.

“We go.” he says.

Your brows knit.

“Where?”

He grips your jaw lightly, forcing you to hold still for his words.

“To someone who knows.”

You frown.

“Merfolk.”

“Yes.”

“And they can— help me?”

“He will,” Sukuna says, and the certainty in his tone isn’t optimism. It’s a threat made into a promise. “Or I will take his arms.”

Your eyes widen, and despite everything, you manage a weak scoff.

“That’s… very diplomatic.”

Sukuna’s mouth curls.

“It is very effective.”

You swallow, then look down at the ocean as if it might bite you back.

“Will they… want to help me?”

He watches you flinch inward, sees the human fear of being unwanted, of being judged, of being called an intruder.

“You do not beg,” he says, voice low. “You do not apologize. You want to live in the sea. That is enough.”

You stare at him.

“You’re sure?”

He tightens his grip on your arm.

“Yes.”

You don’t argue, you’re too tired.

He drags you closer to the waterline, and this time you don’t resist. You let him lift you, tuck you against his torso the way he does when he carries you through water. His body is so warm. Heavy. Safe in a way you shouldn’t trust and do anyway. You always do.

“Hold.” he orders once again.

You wrap your arms around his neck and cling as much as you can.

He sinks into the water with you, smooth and controlled, keeping your face above the surface until the last second. He watches your expression as if trying to memorize it, as if fearing you’ll vanish before he can finish what he started.

Then he dives.

The swim to Suguru is long.

Sukuna doesn’t tell you that in numbers, because numbers mean nothing to you out here. He tells you with his pace — steady, relentless, choosing currents that help, choosing depths that keep you from freezing too fast.

He surfaces often enough that you can breathe without choking on waves. When you tire, when your arms go slack around his neck, he tightens his hold and forces you to cling again with a rough nudge.

He doesn’t let you drift.

At some point you stop trying to keep track of direction. The island disappears behind you and the world becomes water and movement and the occasional patch of sky. You feel your body change in small ways during that travel — your chest doesn’t panic as violently when you’re submerged, your lungs ache less sharply, the cold doesn’t cut as deep.

You taste salt on your tongue and it feels less like discomfort and more like something your mouth expects.

Sukuna notices everything.

He notices the way your breath slows instead of spikes. He notices your body going looser in his arms, less stiff with fear. He notices your skin holding warmth a fraction longer after surfacing. The symbiont is already easing and blurring the edges of your humanity, making you more compatible with his world.

It makes him tense instead of comforting him.

Because it means the sea has already started claiming you, and he doesn’t know what else it will change.

He doesn’t know what it will demand.

When he finally slows, the water around you shifts. The current becomes gentler, the sea floor rises enough that light reaches it in clearer bands, kelp forests sway below like dark curtains.

The place feels… occupied. Not in a way you can see immediately, but in the way your skin registers attention coming from somewhere.

Sukuna surfaces near a rocky outcrop that juts from the water like a broken tooth. He holds you upright, arm locked around your waist, and scans the water.

“Stay quiet.” he says near your ear.

You manage a hoarse whisper.

“I’m always quiet now.”

His hand tightens slightly, displeased, and you shut up.

The water ripples near the rock, and something rises.

At first you think it’s just shadow.

Then you see the arms — thick, dark purple, dotted with suction cups, moving with slow elegance. A head breaches briefly, dark hair slicked back, eyes half-lidded with a calm intelligence that makes your stomach flip.

Suguru surfaces like he’s stepping into a room, not emerging from an ocean.

Human-looking from the waist above, — except for the fins similar to Sukuna’s on his forearms — giant octopus from the waist below. Majestic in a way that leaves you a little dizzy.

He looks at Sukuna first, then at you.

His gaze lingers, assessing, not unkind but sharp.

“You brought me a human,” he notes, voice smooth, amused in a way that makes your skin prickle.

Sukuna’s jaw tightens.

“You talk too much.”

Suguru’s mouth curves in a sly smirk.

“And you… are talking. Human language. That’s how I know this matters.”

Sukuna shifts you closer to his chest, possessive.

“She is dying.”

You hate being spoken about like you’re not there, but you don’t have the energy to fight it. You cling to Sukuna’s shoulder and stare at Suguru, trying to read him.

Suguru’s expression changes subtly.

The amusement fades into something more focused.

“Dying how?”

Sukuna’s eyes narrow, brows knit together and the corner of his lips twitch.

“Weak. Sun. Hunger. Blood. Human problems.”

Suguru’s gaze drifts to your throat, to the line of your jaw, to the way your lips look a little too pale. Then his eyes narrow slightly, as if he’s seeing something you can’t feel yet.

“And saltblood.” Suguru says quietly.

You fell a twinge of panic inside your chest.

“You can tell? So it’s really in me…”

Suguru looks at you directly now, and his voice softens a fraction.

“It is.”

Sukuna’s grip on you tightens.

“Fix it.”

Suguru sighs like you’re all inconveniences.

“You can’t fix a becoming. You can only guide it.”

Sukuna bares teeth and barks the word like an order.

“Guide.”

Suguru’s gaze flicks to Sukuna’s mouth, then to yours, and something like understanding sharpens in his eyes.

“You are the one who fed it to her.”

Sukuna goes still for a moment.

You feel his chest tighten against your cheek.

Suguru continues, tone clinical despite the setting.

“Breath-sharing, skin contact, blood exchange… Breeding.” His eyes linger on Sukuna’s face like he’s enjoying making him uncomfortable. “Multiple points of transfer.”

Sukuna’s jaw works.

“I did not—”

“You did,” Suguru interrupts, easy. “Not on purpose, maybe. But saltblood doesn’t care about your intent. It cares about opportunity. A stressed human body is an open door.”

You squeeze your eyes shut briefly, the reality of it sitting heavy in your stomach.

Suguru’s gaze returns to you.

“How long since you had human support? Food, medication.”

“Weeks.” you whisper.

Suguru hums.

“That’s plenty. Starvation, lack of vitamins and stress accelerate adaptation. It’s trying to keep you alive the only way it knows how.”

Sukuna’s voice turns low.

“So do it.”

Suguru lifts a brow.

“Do what?”

“Make her live in the sea,” Sukuna demands, and the words come out like an order he’s giving the ocean itself. “Make her like us.”

Suguru studies him for a long beat.

“And are you prepared for what that means?”

Sukuna’s mouth tightens a fraction before he speaks.

“She said it is her dream.”

Suguru’s gaze flicks to you and he hums.

“Is it.”

Your throat tightens. You’re exhausted. You’re frightened.

You’re also staring at the only door left that doesn’t end in you dying on rock.

“Yes,” you say, and your voice shakes, but the word itself doesn’t. “If it means I live.”

Suguru nods slowly.

“Then we do it properly.”

Sukuna’s grip on you eases a fraction, relief and tension mixing into something that makes his shoulders tighten.

Suguru continues, tone shifting into something like ritual without losing its practicality.

“A human can’t just be dropped into saltblood and expected to survive. Your organs have to acclimate. Your blood chemistry has to shift. Your throat has to learn what to do with water without panic. Your skin has to change so you don’t lose heat too fast, so you don’t split open in salt.”

He tilts his head.

“And you need a species track that fits you.”

Sukuna answers immediately, like he’s already decided. Because he did.

“Seal.”

Suguru’s gaze flicks to him, amused again.

“Of course you’d pick prey.”

Sukuna’s eyes flash.

“I picked endurance.”

Suguru’s smile widens slightly.

“Sure.”

He looks back to you.

“Seal is good. Amphibious. Warmth retention. Breath control. It will let you surface and rest when you need. It will give you a way to exist in both worlds without tearing in half.”

Your stomach twists with hope that feels dangerous.

“Will it hurt?”

Suguru’s expression doesn’t soften.

“Yes.”

Sukuna’s hand tightens on you again.

Suguru lifts a hand — one human-shaped, edged with the suggestion of webbing and suction.

“Not like a blade. Like a slow rearrangement. Like your body learning a new law.”

“She is already hurting.” Sukuna grouses, his tone has a twinge of urgency.

Suguru nods.

“Which is why we do it now, while saltblood is already moving, before lack of vitamins kills her faster than adaptation can save her.”

You swallow hard, your eyes dart to your own hands, Sukuna’s face and then go back to Suguru’s.

“What do I— have to do?”

Suguru’s gaze slides to Sukuna, then back to you.

“You have to choose it every day. You have to eat what the sea offers. You have to let your body stop clinging to land as the only safety. And—” his eyes sharpen, “—you need a guardian through the worst of it.”

Sukuna bristles.

“She has me.”

Suguru’s smile is thin.

“You are a predator, Sukuna. You keep what you want. That’s not the same as guiding.”

Sukuna bares teeth again, huffing.

“Watch your mouth.”

Suguru doesn’t look afraid.

“Watch yours. If she panics mid-change, she drowns. If her body rejects saltblood, she burns with fever and dies. If she doesn’t eat, she dies. If she eats wrong, she dies. If you get impatient, she dies. Are you willing to gamble with her life?”

The word dies pierces his chest like a harpoon.

Sukuna’s jaw tightens so hard you can feel it against your cheek.

Suguru looks at you again, calmer.

“You’ll need community contact too. Not everyone will welcome you. Some will. Some won’t. But you can’t be only his.”

Sukuna’s arm clamps around your waist, territorial, possessive enough that you gasp as he brings you closer, almost squishing you against him.

Suguru’s eyes flick to the grip.

“That,” he says mildly, “is exactly why I said it.”

Sukuna’s voice turns low, dangerous, as he grits through his teeth.

“She is mine.”

Suguru’s smile is faint.

“If you want her to live, you will share the ocean.”

Silence stretches. The kelp sways below like it’s listening.

Sukuna doesn’t like it.

He doesn’t like being told what to do.

He doesn’t like the idea of you having a life that isn’t tied entirely to him.

He also doesn’t like the idea of you dying.

He exhales hard through his nose, then says, rough,

“Fine.”

Suguru’s eyes gleam with satisfaction.

“Good.”

He gestures toward the rock outcrop, and his tentacles rise and move, anchoring him as he shifts position. It’s hypnotizing to watch how elegantly his movements are.

“We start with stabilizing. You’re malnourished, anemic, dehydrated. Saltblood can help, but it can’t conjure flesh from nothing.”

Sukuna snarls softly at the clinical terms like they’re insults.

Suguru continues anyway.

“We’ll get her warm. We’ll get her fed. Then we’ll begin guided exposure — safe depths, controlled breath, gradual pressure. We’ll coax lamellae formation at the jawline. We’ll teach her throat to accept exchange. We’ll let the seal track settle.”

Your heart pounds.

“Lamellae.”

Suguru nods.

“You’ll feel it before you can see it. A soreness under the jaw, a tightness when you swallow. Don’t claw at it. Don’t panic.”

Sukuna’s voice cuts in, low.

“If she panics.”

Suguru’s gaze flicks to him.

“You hold her.”

Sukuna’s pupils flare.

The instruction hits some possessive part of him that wants to claim it, wants to make it a promise.

He tightens his hold on you as if proving he already knows how.

Suguru’s eyes soften — barely.

“You’re already changing, girl.” he tells you. “That’s why you’ve been holding breath longer, why salt tastes like need, why your body doesn’t revolt as hard when you’re submerged. The symbiont is already writing itself into you.”

You shift slightly in Sukuna’s grip, worried but with a faint relief surfacing.

“So I’m not just… dying.”

Suguru shakes his head.

“You’re adapting. You can see it as dying to live again. Metamorphosis. But adaptation without guidance is ugly. It can go wrong.”

Sukuna’s voice is quiet, and you’ve learned that quiet means serious.

“It will not go wrong.”

Suguru’s gaze slides to him and he frowns slightly.

“That’s a lot of confidence for someone who didn’t even know what he was doing to her.”

Sukuna’s jaw clenches and a flicker of something crosses his face — irritation, guilt, something he doesn’t like enough to name. He doesn’t apologize. He doesn’t soften. He just tightens his hold and says, rough, low against the side of your head.

“I kept you alive.”

You manage a weak sound that could be a laugh, your hand slides softly on his chest, a brief caress.

“You did.”

Suguru watches the exchange with an expression that suggests he’s seeing more than either of you wants him to.

“Bring her,” he says at last, and the water around him shifts as if responding to his presence. “There’s a sheltered inlet near here. Warm current. Less surf. You can rest there while we start.”

Sukuna doesn’t hesitate. He moves immediately, carrying you with the same controlled strength that got you through the tunnel. You cling to him, head against his shoulder, the relief of having a plan making your body feel suddenly heavier.

As he swims, Suguru follows beneath the surface, arms streaming like dark ribbons, moving with eerie grace.

Sukuna keeps you close and high, surfacing often enough that you can breathe without struggle. His grip never loosens, his attention never leaves you for long.

He’s attached.

He hates that word.

He hates what it implies — that he can be hurt.

He tells himself it’s not attachment.

It’s possession. It’s priority. It’s practical.

Humans are fragile and you’re his human and losing you would mean… inconvenience.

The lie doesn’t hold.

When you shift in his arms and murmur, barely audible, “Thank you,” something inside him tightens so sharply it feels like pain.

He answers with the only thing he can manage without sounding weak.

“Do not die,” he growls near your ear. “Not now.”

You exhale against his neck, exhausted.

“I’m trying.”

He presses his mouth briefly to your temple — too fast to be called tenderness, too deliberate to be nothing — and then he swims harder, as if speed alone can outrun the idea of you leaving him in the final way.

The ocean opens ahead into a darker corridor between rocks.

The water warms subtly as you enter it, and for the first time in days your muscles loosen without you forcing them.

Sukuna feels it too. He adjusts his hold, tucking you closer, bracing you against his torso as if the warmth is something he can shield you inside.

Suguru surfaces beside a rock shelf and looks up at you with calm focus.

“We will make you sea,” he says, voice steady. “But you have to let go of land.”

Your throat works, eyes stinging.

“I already did.”

Sukuna’s hand tightens on your waist.

He doesn’t look at Suguru when he answers, but his voice is rough and certain.

“She will live,” he says. “Even if it binds her to the ocean. Even if it binds her to me.”

And he means it like a vow he doesn’t know how to pray, only how to enforce.

Sukuna also learns quickly that saving you is not a single act.

It isn’t as simple as dragging you through a tunnel, forcing air into your lungs until you stop sinking into darkness. It isn’t finding shelter, fish, warmth.

Those are the simple, manageable parts, the parts he understands — keep the body fed, keep it from freezing, keep it from getting torn open by the world.

This is slower. Meaner. It happens under skin.

In the sheltered inlet Suguru chooses, the water is calmer, warmer in a way that makes the edge of the cold less sharp. The rocks form a crooked bowl that breaks the surf. Kelp drifts along the mouth of it like a curtain, and the current brings heat in lazy pulses.

Sukuna can taste the difference, he can feel it in the way his muscles loosen when he rises onto stone.

He gets fully out of the water more than he ever does.

Not because he needs to — because you do.

You’re laid on a flat stretch of rock above the tide line, wrapped in what you have — damp cloth, Sukuna’s arms and torso, the warm press of his body curled around you as close as he can make it without crushing you.

Suguru told him you need heat, consistent heat, not the violent kind of heat that cooks prey and turns blood into scent.

Sukuna gives you what he can.

He braces himself around you, broad chest against your back, one arm hooked around your waist like a barrier. When you shiver, his hold tightens. When you go still and your breathing turns thin, he leans in until you can’t drift away from the warmth he’s offering. His shark half stays in a shallow pool beneath the rock shelf, even with him curled around you, tail occasionally moving to keep his weight balanced, but the rest of him is on land with you, stubbornly, as if the stone is something he can conquer by refusing to leave it.

Suguru watches from the water.

He is too calm for the situation. Too composed. He surfaces only when he wants, all those tentacles moving with quiet precision, suction cups anchoring him to rock as if gravity is optional. His eyes track your face, your throat, your hands. His gaze is clinical, but not cold.

Sukuna hates that, too.

He hates that Suguru can look at you like a problem to solve without flinching.

He hates, most of all, that he needs him.

“She’s already running hot,” Suguru says on the first day, voice steady. He doesn’t soften the words to spare feelings. “Feel her.”

Sukuna’s hand is already on you, palm pressed to your stomach, fingers spread under your ribs. Your skin is warm, then warmer, then too warm. You sweat in small bursts even when the air is cool. Your lips are dry. Your eyes look heavy.

“You’re burning,” Sukuna mutters near your ear, and his tone turns it into accusation as if you’re doing it to spite him.

You try to laugh. It comes out weak, and it ends in a swallow that hurts.

“It’s… fine.”

Suguru makes a sound that is almost humor.

“No. It’s normal.”

Sukuna’s eyes narrow.

“Normal is what she does when she is not dying.”

Suguru’s gaze flicks to him, unimpressed.

“Normal for saltblood. Normal for a body that’s being rewritten.”

You shift slightly, a small restless movement, and Sukuna’s arm tightens around you, anchoring you again. He doesn’t like the way you move when you’re uncomfortable. It makes him think of prey trying to crawl away from a wound.

Suguru comes closer, tentacles rising onto the rock shelf. One of them brushes your wrist, gentle at first, then firmer as if checking pulse. Feels cold, silky and slimy in a way only sea creatures can offer. Another slides along your jawline, not touching your mouth, just mapping.

You flinch, half-asleep, and Sukuna’s entire body goes rigid.

“Don’t.” Sukuna snaps, brows knit tight, nose wrinkling, teeth bared.

Suguru doesn’t look at him.

“I’m not hurting her.”

Sukuna’s pupils widen anyway, anger flashing hot. His claws flex against stone.

“You touch without asking.”

Suguru finally glances up, eyes calm.

“If I ask, she might say yes to be polite. Or say no because she’s frightened. Neither helps. I’m reading her body, not her manners.”

Sukuna hates that, too, because it’s true. You have always been the kind of human who tries to be reasonable even when you’re breaking.

Suguru’s tentacle presses lightly under your jaw.

“Swallow.”

You blink, slow, and obey. Your throat works. You wince.

Suguru hums, satisfied and concerned at the same time.

“The lamellae are starting. That’s good.”

You try to focus, to remember what he said, brows knitting together.

“Breathing surfaces,” Suguru explains to you, simple. “Not gills like a fish. Not yet. Think of it like your throat learning a second language.”

Sukuna’s jaw tightens at the phrase. Second language. He taught you one already, and you taught him one as well. He watched you struggle and then succeed, watched you learn him as he learned you.

It did something to him.

This will do worse.

You lick your lips.

“Is it… dangerous? To me?”

“It can be,” Suguru answers. “If it swells too fast, if you panic, if you don’t eat, if you keep trying to live like a land human while your body is begging for water adaptation.”

Sukuna’s grip around you tightens again, a warning.

“She will eat.”

You mumble something that might be agreement, then your eyelids drift. Your head lolls slightly against Sukuna’s shoulder.

Suguru watches the movement, then says,

“You need to drink, too.”

His gaze slides toward the inlet.

“Saltwater is what we have. Better than nothing, but not enough. She needs fresh water too, or she’ll cramp and her heart will race and her fever will climb higher than it has to. You have rain here. Catch it. Store it in rock bowls. Make it a priority.”

Sukuna doesn’t like being told what to do.

He likes even less the realization that he didn’t think of it fast enough.

He leaves without a word, slipping back into the water, tail cutting a clean path. You stay on rock, curled near the fire, Suguru paying close attention to your weak form. He returns with broad leaves and seaweed and hollowed driftwood he wedges into rock angles so rain will funnel into a basin.

It isn’t pretty. It works.

That night the fever climbs.

Sukuna feels it in the way your body goes too hot against his chest even now that you’re completely bare, — skin on skin raises the warmth your body receives from his — in the slick sweat that coats your neck and makes your hair cling.

You shiver even as you burn, muscles fluttering with tremors that make you look small.

He hates how small you look.

You start to mutter, unfocused words slipping out of you — half sentences, fragments, your voice thin like it might snap. Sukuna presses his mouth to your temple and tells you to be quiet, tells you to sleep, tells you to stop making sounds that make his skin feel tight.

You don’t listen.

You can’t.

Your body twitches, and then you jerk suddenly, startling awake with a gasp like you’re drowning on air. Sukuna’s arm clamps around you, holding you in place.

“Breathe.” he growls.

You claw weakly at his forearm.

“Hurts—”

Sukuna’s jaw tightens and his gaze racks down your body.

“Where.”

“All—” you swallow. Your throat works wrong. “My throat.”

Suguru rises onto the rock shelf immediately, faster than his calm usually suggests.

Tentacles reach for you, and Sukuna’s eyes flash crimson around black, murderous.

“Touch her and I’ll—” Sukuna starts.

Suguru cuts him off without even looking at him.

“If you threaten me while she’s spiking, you’re wasting her time.”

The tentacles wrap around you with controlled firmness — one around your wrists, one across your thighs, another anchoring your shoulders. Not crushing, just tight and firm enough to stop you from jerking and tearing yourself open on rock.

You struggle weakly, the fever making you frantic.

Sukuna feels the panic in your body like a current running through him. It makes him want to bite. It makes him want to kill something. It makes his vision sharpen until all he can see is the fragile line of your throat moving too fast.

“Let go.” Sukuna snarls at Suguru, irrational for a second.

Suguru’s eyes flick to him, calm and hard.

“If she thrashes, she swells more. If she swells more, she closes the airway she’s building. Do you want her to live, or do you want to feel in control?”

Sukuna’s teeth grind and that growl rumbling from deep in his chest echoes.

Your voice breaks into a whine that twists in his gut. You look at him through half-lidded eyes, not fully seeing him, and that does something worse than fear.

It makes him feel guilty, sharp and ugly.

Because this is his fault.

He insisted you came.

He pulled you into water.

He kept you close.

He fed you saltblood, not on purpose, when he ate you out, when he fucked you and when he gave you oxygen. He knew the risks and he did it anyway without telling you what it could do to you.

He wanted you alive with him, wanted you where he could watch you, keep you, not lose you.

Now you’re paying for it with fever and pain and the looming possibility of death.

Sukuna forces his hands to stay still. He leans in behind you once again, bracing your back, his heat pressed against you like armor even with Suguru’s tentacles still holding you. He presses his mouth to your ear.

“Hold still.” he orders, voice husky. “Do not fight him. Fight me instead.”

Your breath stutters as you make a broken sound, then sag a fraction as if his voice is the only familiar anchor you have.

Suguru uses that moment.

One tentacle slides under your jaw, lifting slightly, encouraging your airway open. Another presses along the side of your throat with careful pressure, not squeezing — guiding swelling away from a critical point. A third tentacle dips into the water and comes back wet, then drags cool seawater across your neck and collarbones in steady strokes to pull heat down.

Your shivering eases a fraction.

Suguru speaks to you in the same calm tone he uses for Sukuna, as if your fever isn’t a crisis, only a phase.

“You’re safe,” he croons. “You’re not choking, your throat is changing. It feels wrong because it is wrong, but it isn’t killing you.”

You swallow with difficulty.

“Feels like—”

“I know, dear.” Suguru says simply. “Breathe slow. Through the nose. Don’t gulp air. Don’t chase it.”

Sukuna watches your chest rise and fall. He watches Suguru’s tentacles work like tools, and it’s infuriating that he can’t do that, he can only hold you and keep you warm and feed you and threaten the world.

Your fever breaks near dawn.

It’s a slow shift.

The heat stops climbing and begins to slide down, sweat cooling on your skin. Your muscles stop trembling. Your breath steadies. Your eyes finally close in real sleep, not the frantic half-wakefulness of pain.

Suguru loosens the tentacles slowly, one at a time, testing whether you’ll jerk.

You don’t.

Sukuna keeps his arm around you anyway, tighter than before.

He stares at Suguru like he’s deciding whether to thank him or rip him apart for touching you.

Suguru, infuriatingly, doesn’t react. He simply says,

“That was the first hard spike. There will be more.”

Sukuna’s jaw clenches and his nostrils flare.

“How many?”

Suguru’s eyes are calm.

“As many as it takes for her body to stop fighting the idea of the sea.”

Sukuna looks down at you, sweat-damp, sleeping against him.

“She wants it.” he mutters more to himself than to anyone else.

Suguru’s mouth curves slightly.

“Her mind might. Her body is still human. It will test the change. It will panic and rage and cling to old rules. You can’t bully biology into being quiet.”

Sukuna’s eyes flash with something akin to dare.

“Watch me.”

Suguru snorts.

“You’ll try. You’ll fail. Then you’ll learn patience.”

Sukuna would normally snap back. He would normally punish disrespect.

He doesn’t.

Because you shift slightly in your sleep, seeking warmth, and Sukuna’s entire attention collapses inward as he curls once again around you to keep you hot and as comfortable as he can.

He keeps you close and decides that any energy wasted on Suguru’s mouth is energy not spent on you surviving.

Suguru’s guidance is not only touch and water and restraint.

It’s also stories.

He tells them when you’re half-awake, when your eyelids flutter and your mind keeps sliding into exhaustion.

He speaks in a low voice that carries over the water and into the rock bowl of the inlet. He speaks while Sukuna feeds you small pieces of fish, holding them to your mouth like you’re fragile, like you can’t be trusted to chew without falling apart.

Suguru watches Sukuna do it, then keeps talking anyway.

“Merfolk aren’t a separate miracle,” Suguru says one afternoon when the sun is high but the inlet keeps you shaded. “They’re a choice ancient humans made when the sea offered survival.”

You blink slowly, face slack with fatigue.

“Ancient humans… Neanderthals…?”

Sukuna’s grip tightens slightly around your waist as if the word human belongs to him and he doesn’t like hearing it said too softly.

Suguru continues.

“Early humans lived near coasts. Storms came, hunger came, disease came. Some kept moving inland. Some stayed. The ones who stayed watched the sea and learned patterns. They learned that some creatures survived pressure, cold, salt. They learned the sea holds a kind of life that land doesn’t.”

You swallow a bite of fish with effort. Sukuna’s thumb brushes your jawline, feeling the subtle swelling there.

Suguru’s gaze flicks to the motion, then back to you.

“There were symbionts — microscopic, yes, but not small in effect. They lived in certain marine species. In mucus. In blood. In the skin’s oil. They made bodies tolerate salt and oxygen scarcity better. They made wounds close faster in cold water. They made panic less violent because panic wastes oxygen.”

You breathe shallowly, listening.

“Some humans,” Suguru says, “got exposed by accident. Cuts in saltwater. Eating raw marine flesh. Sharing breath in desperation. The symbionts didn’t care what host they used. They adapted. They colonized. They offered survival, but they demanded change. Many died while trying to adapt, while learning what would keep them alive.”

Sukuna watches your face as you listen.

He watches for fear, for rejection, for the moment your mind decides this is too much.

You don’t pull away.

You look hungry for the story, not just food.

Suguru’s voice stays steady.

“It wasn’t instant. It took generations. People who accepted the changes lived longer in water, hunted better, escaped land conflict. Their children inherited a body more tolerant of the symbiont, already changed, already improved and hybrid. Over time, it wasn’t a disease. It was heritage.”

You whisper, hoarse.

“So merfolk… are— were humans.”

Suguru tilts his head.

“Some would punch you for that. Some would laugh. The truth is old enough that it doesn’t matter. They are merfolk now, hybrids. They belong to the sea in ways land humans don’t understand.”

Sukuna’s jaw tightens, already irritated at the idea of you belonging anywhere he cannot follow — even if he is the sea.

Suguru looks at Sukuna as if reading the possessiveness.

“And the ones who stayed on land,” he adds, “didn’t become lesser. They became different. They built rules and walls and tools and cities. They forgot the ocean’s laws because they didn’t have to live by them.”

Sukuna’s eyes narrow.

“They build cages.” he says flatly.

Suguru nods.

“Yes. Cages. Because they fear what they can’t control. Because they fear what survives without them.”

You swallow, eyes closing briefly as if the words are too heavy to hold while awake. Sukuna adjusts his hold, tucking you closer, bracing you against his heat.

Suguru’s stories become part of the treatment.

He uses them to keep your mind tethered when your body burns.

He uses them to give you something to chase besides pain.

When fever spikes again — less violent than the first, still enough to make you cry quietly into Sukuna’s arm — Suguru speaks over it, tone calm, telling you about the first coastal clans that learned to dive without fear, about children born with stronger breath holds, about elders who taught breathing as a craft, not instinct.

Sukuna hates hearing you plead, because your voice doing that does something to him, it drags him toward a rage he can’t spend anywhere useful. He wants to make your pain go away and he can’t.

It makes him want to blame someone.

It makes him want to tear the world until it gives you relief.

He keeps his mouth shut.

He keeps his body pressed to you.

He lets Suguru’s tentacles hold you when you jerk.

He tells himself he’s doing it because Suguru is right and panicking will kill you.

He tells himself he’s doing it because he’s disciplined.

The truth is simpler — he can’t risk hurting the only one who knows how to keep you alive.

Between spikes, Suguru makes Sukuna work.

“Feed her more,” Suguru says, and it isn’t a suggestion. “Fatty fish. Liver. Shellfish if you can find it. Seaweed that’s safe. She’s rebuilding blood, she’s building new tissue, she can’t do that on empty stomach.”

Sukuna hunts farther, dives deeper, returns with richer prey. He tears it into smaller pieces because you chew slower now, but you eat raw. He holds it to your mouth because your hands shake sometimes when you’re too weak. He doesn’t speak while he does it he refuses to acknowledge the softness in the act. Even if it’s obvious.

Suguru adds salt in controlled amounts — your chemistry is shifting and the symbiont thrives when the environment inside you stops being hostile. Suguru makes you drink rainwater when you can keep it down. He uses cool seawater on your wrists and neck during spikes. He uses warm water during chills to stop you from shaking so hard you exhaust yourself.

He checks your throat daily.

Sukuna watches those checks with fury simmering in his chest. Suguru’s tentacle slides along your jawline, presses gently behind your ear, traces the line of your neck where swelling builds.

Each time you flinch, Sukuna’s pupils flare.

He never strikes.

He never even snaps again after the first day.

He simply watches, vigilant, jaw tight, and keeps his heat on you like a shield.

At night, when you finally fall into deep sleep, Sukuna lies behind you on the rock shelf once again, fully out of the water, even his shark half, his arm locked around you, every possible inch of his skin touching you to seep his warmth into your body. He keeps his face close to your neck, breathing you in to reassure himself you’re still there, still warm, still his.

That’s usually when guilt bites harder.

He thinks of your old life in ugly flashes — not because he respects it, but because he knows you did.

The facility’s food, your medications, your clothes that didn’t smell like smoke and salt. Your information, your sense of where you were, what day it was, what you were allowed to expect.

He thinks of you losing all of it because he told you to come.

Would you hold it against him?

Maybe you already do.

Maybe you’re just too exhausted to show it properly.

He told himself you’d be free.

He didn’t admit that freedom in the ocean is harsher than any human room if your body isn’t built for it.

If you die now, there’s no undoing it.

There’s no “go back.”

There’s only him, alone again, with the ocean and a memory of softness and stubbornness that will not shut up.

He hates that thought enough that he shifts closer, presses his mouth to your shoulder, and holds you harder as if pressure can keep you from slipping away.

Suguru notices the attachment without commenting.

He watches Sukuna hover like a guard dog that refuses to sleep, and he says nothing until the day you’re strong enough to sit upright without swaying.

It happens quietly.

One morning you blink awake and don’t immediately look like you’re bracing for pain. Your skin still looks tired, but your eyes are clearer, your breathing is steadier, your throat doesn’t strain as much when you swallow.

You drink rainwater without gagging.

You eat a full piece of fish without stopping halfway.

Sukuna watches the small changes like they’re miracles he refuses to call miracles, but his face lights up in a way you can notice if you spend too long with him.

Suguru surfaces beside the rock shelf, eel-thin shadows twisting behind him in the water. Two figures slip up near his shoulders.

Sukuna glares, distrustful.

“Who?”

Suguru doesn’t look at him, he looks at you.

“Mimiko. Nanako.”

They surface properly now, near the rock shelf with a confidence that makes Sukuna’s posture tighten.

Mimiko and Nanako.

Eel hybrids, long-bodied in the water, upper halves human enough to read expressions, lower halves sleek and powerful, skin patterned in subtle bands that shimmer when they turn. Their eyes are bright, sharp, curious in a way that feels dangerous because it’s social.

They look at Sukuna first, and their mouths pull into matching smirks like they share one thought.

“He’s brought a human.” one of them says — Mimiko, voice light, almost sing-song.

“And he looks like he wants to bite someone.” the other adds — Nanako, amused.

Sukuna’s lip lifts, teeth flashing.

“Keep your distance.”

Nanako laughs.

“He does want to bite someone.”

Mimiko’s gaze slides past him to you, and the curiosity shifts.

Not predatory. Appraising. Like they’re trying to decide if you’re fragile or stubborn or both.

“That’s her.” Mimiko says quietly, the tone changing. “She’s smaller than I imagined.”

You flush despite yourself, embarrassed and tired.

“I can hear you.”

Nanako’s smile widens.

“Good. That means you’re awake.”

Mimiko drifts closer, stopping just outside Sukuna’s reach like she’s testing his temper.

“Suguru says you’re becoming,” she says, voice less playful now. “Is that what you want?”

You swallow that painful tightness.

“I want to live.”

Nanako tilts her head.

“That’s the right answer.”

Mimiko’s gaze flicks to Sukuna’s arm locked around you.

“And him?”

Sukuna’s grip tightens automatically, possessive spike flashing hot.

“Mine.” a low growl.

Nanako rolls her eyes dramatically.

“We heard.”

Mimiko’s mouth twitches.

“He doesn’t share.”

“He will,” Suguru says, and there’s a quiet authority in it that makes Sukuna’s jaw clench.

Nanako circles slightly, eyes on you.

“Do you know what you’ll be?”

“Seal,” you answer, voice hoarse.

Mimiko’s brows lift.

“Warm. Good. Less likely to freeze and die when you get stupid.”

You blink.

Nanako grins.

“That was a compliment.”

Mimiko’s gaze softens a fraction.

“We’ll show you how to eat properly,” she says. “Not just fish until you rot from lack.”

Nanako adds, almost offhand,

“And how to sleep in water without dreaming you’re drowning.”

Your chest tightens at that. The offer lands heavier than their casual tone, it feels like acceptance.

Sukuna watches your face, sees the small flare of hope you try to hide.

It hurts him in a way he doesn’t know what to do with.

He wants to pull you back, keep you in his arms, keep you as the world’s smallest circle.

He also remembers Suguru’s words — you can’t be only his.

So he stays still, jaw tight, and lets you look at them.

You shift slightly, not leaving Sukuna’s hold but leaning forward enough to show you’re listening.

“I don’t… know the rules.”

Mimiko’s expression turns sharp.

“Rule one, don’t apologize for needing help.”

Nanako nods.

“Rule two, don’t let him scare you into silence.”

Sukuna growls softly.

Nanako grins at him without fear.

“See. Like that.”

Mimiko’s gaze slides to Sukuna, then back to you.

“We’re not humans,” she says, voice steady. “We won’t cut you open. We won’t call you specimen. If you become, you become. If you don’t, we mourn. That’s it.”

Your throat tightens again but not because of the transformation. You glance at Sukuna, and he can feel the way your trust in him shifts — doesn’t lessen, but expands.

You’re letting other voices in.

It makes him want to bite someone again.

He restrains himself.

It’s been a stressful journey for him.

Suguru watches him with quiet satisfaction, then looks at you.

“Tomorrow,” he says, “they’ll take you through shallow currents. Teach you how to move without fighting. Teach you the signs when lamellae open and when they close. Teach you what to eat when fever threatens.”

Nanako’s grin turns wicked.

“And we’ll teach you how to ignore him when he sulks.”

Sukuna huffs.

“I do not sulk.”

Mimiko laughs softly.

“You sulk like a storm cloud.”

Sukuna’s eyes flare, and for a second the urge to lash out surges hard—

Then you lean back into his chest, tired, warm, safe, and your hand lifts weakly to rest against his forearm like you’re grounding yourself in him.

The contact stops him cold.

He presses his chin to the top of your head, rough and possessive, and forces his breathing to stay even.

He doesn’t know how to be gentle without feeling trapped.

He doesn’t know how to share without feeling like he’s losing.

But he knows this — you’re still here.

You’re breathing.

You’re changing, and it’s ugly and painful, and it’s saving you.

He watches Mimiko and Nanako drift closer, not touching you yet, just letting you see them, letting your mind accept that there are others in the sea who don’t look at you like prey or experiment.

And he stays there with you, braced on the rocks, nearly etirely out of the water, accepting the discomfort because it keeps his heat close to your skin.

Suguru’s voice softens a fraction when he speaks again, not warm, but less sharp.

“You wanted the ocean,” he says. “Now you’re paying the entry price. That doesn’t mean it isn’t worth it.”

You nod slowly.

Sukuna watches your nod like it’s a vow you’re making to something he can’t compete with.

He only leans in and presses his mouth briefly to the side of your head, a rough, wordless promise that you’ve started to see as affection — his way of showing care. You like it, and you say nothing because it would make him bristle and snap at the mere suggestion of showing he has a soft side.

He will keep you alive long enough to become what you asked for.

Because if becoming binds you to the ocean, he can live with that. He can live with anything, as long as you don’t leave him for good — as long as you’re alive and where he can find you.

Even if it binds you to him in a way he can’t pretend is only convenience anymore.

a/n:

I decided to shove the angst and the possibility of happiness in a single place because I do hate myself, after all. This chapter has both Reader and Sukuna's POV in a single go, it's mixed, it's mingled, because well… they are now hardly one without the other. Also, this lore is the beginning of the lore of any hybrid AUs I write, so keep that in mind! Humans are kinda fucked up and they had to hunt a lot of Merfolk and do their little science to start developing technology to create mammal-hybrids and etc. We do love to play god.

It's an open ending! If you want me to give them a closure I will commit a gojo satoru in front of your eyes 👁️👄👁️

Trending Tags

Last Seen Tags

#shark!hybrid

Trending Tags

Last Seen Tags

#shark!hybrid