Okay time for that marineford au I considered
Essentially just. The whole situation with Sengoku and Garp, where the latter point blank is pinned to the ground and begs Senny not to let him go-
Garp who is flawed and makes poor decisions. Garp who has put his job above most other things the majority of his life. Garp who lost touch with his son by these decisions, Garp who took in Ace (one of the biggest betrayals to the institution he has ever done), Garp who hid him and Luffy both away, Garp who pushed and pushed and pushed for them to become Marines because that was the only option he could fathom to keep them safe and keep his power over the situation, Garp who made bad choices with the best intentions-
Garp has lost one grandson already to the people he is meant to serve.
Garp had to watch on as Ace knelt on an execution platform, dead eyed and terrified - not of his own death, no, but of deaths of the people who showed up for him.
Garp had to watch as one grandson was nearly taken while another ran full throttle through a war ground to save the other. He accepts the hit and hits the ground in a mix of allowance and genuine pain. Luffy doesn't always know his own strength, especially when someone is between him and his goal.
Garp goes down and he prays to every deity he can think of that his boys will be safe.
Akainu moves, and Garp moves to lunge. Sengoku shoves him into the stone ground, cracking the rock and pinning him in place. And Garp? Garp is Done.
He has lost his son. He lost a grandson. He lost friends, he lost so much in name of the greater good, but is it even 'good' if all it reaps is suffering? After all the things he's done, is he even a good man?
He's made so many choices for the Marines that keep him up at night.
He refuses to continue that cycle.
He turns his head, eyes livid, and he snarls, "I will not lose them, Sengoku. Not like Rosi. If you value me at all, you will let me up."
And Sengoku... falters. He hasn't heard that name aloud in far too long, and he is taken aback. That's all Garp needs.
Akainu is closing in. Luffy is down, his tiny tank of a body finally crashing in the chaotic mess of the past few days, culminating at the worst possible time. Garp is still too far away, but he can see the moment Ace's eyes change, can see when his oldest grandchild makes his decision and moves.
Ace blocks Luffy with his body, anticipating the burning agony with welcoming arms if only to keep his baby brother spared the fate. Luffy is gaping up at him, and he tries a smile to the pale little face staring up to him. There is warmth at his back and it takes a moment to realize the haki signature is familiar, wraps around him in a way he hasn't felt in over a decade. Luffy is not looking at him anymore, he realizes. He turns his head.
Garp is back to back with Ace. He is staring down Akainu, a hole carved and cauterized in his gut. There is blood from his mouth, staining his chin, and yet even the magma now nestled in his abdomen holds no candle to the fire burning in his eyes. Akainu sneers at Garp, mouth opening to spit a comment on treachery and betrayal.
Garp's fist moves faster. Haki covers his flesh and knuckles, cracking across the admiral's face while his other hand holds the man by the collar to keep him in place. One, two three blows are delivered before Garp shifts, lifting and flinging the magma user towards the sea.
Ace stares. Luffy hiccups. Garp turns, staggering. Just as his knees buckle, both both lunge to him, lowering and supporting his weight. Garp clings, hands cupping their heads, pulling them close.
"I'm sorry," he chokes around the blood. "I am so sorry."
The battlefield is quiet, either literally or metaphorically, none of the three know. All they can know at the moment is grasping hands and burning eyes and aching hearts. Luffy curls as close as he can to Garp, huddled close as he can, limbs loose and throbbing. Ace is staring is disbelief.
"You boys..." Garp coughs. "Are my treasure."
"No, Lu. Let grandpa finish..." He gives them both a squeeze. "I made... so many decisions.... ones I never should have." He turns his head, meets Ace's eyes. "Taking you in, calling you mine... that was one of the best decisions I ever made. Portgas D. Ace... you are mine. My grandson. My boy. And I am so... so fucking proud of the man you have become." He takes a shuddering breath. "Your roots do not define... who or how you grow. Whatever you become, you will be perfect. And you will be mine. And I will love you with all I have."
Ace's hiccuping sobs are quiet but jarring. Garp turns to Luffy.
"Lu... my baby, my boy." He cups the teen's cheek, thumb tracing a mirror to the scar on his face. "Since the day you were born, I knew you were destined for wonderful things. I'm sorry for the hurt I have caused. I'm sorry for the things I left unsaid. But you and your brother? You are the best things I have ever chosen. I chose you as a baby. I choose you know. I know you will shake the Seas and Heavens with your laughter, and I will laugh along with you." He pressed his forehead to Luffy's head, pulling Ace closer to cradle both boys close enough to feel their shaking breaths to his throat. He shuddered at the cloying cold that snaked up his bones.
The two boys clung hard to him, even as he began to sag. Between them both, they supported his weight, babbling pleas falling from chapped and bloodied lips.
"It has been... my greatest honor," he choked out, "to raise... the young princes of the sea." He gave them a weak smile. "May the waves carry you far," he recited weakly.
Ace choked. Luffy wailed. Both of them pressed closer, but finished the rite. "And may the winds carry your voice from the heavens."
Garp chuckled. He paid no mind to the blood that bubbled in his mouth from it. He gave them one final squeeze, a weak flex which was nothing like his normal strength.
Two grieving boys cradled the waning life of the grandfather on a war ground.
And with one sacrifice, the tides and paths laid out by Fate skewed.
Monkey D Garp gripped the rights bestowed to him by initial and forced the fates to obey.
A life for a life, an exchange of blood, and overhead, seagulls bathed in black screeched their agreement into the winds and waves and foam. A Deal was struck, the world shuddered, and with one decision, the very fabric of their reality unraveled a tapestry to weave into something new.
At the center of it all was a scarlet ribbon, an orange spark and a spiral of blue.
None on that glorified graveyard knew it then, but the blood of a vice admiral baptized a boy who would be king, purified a boy who renounced his crown, and moved to awaken a slumbering beast Seas away.
