#muscleaugmentation

In-Depth Analysis of the Nomu Species, Prototypes, and Gigantomachia

Introduction

The Nomu, also known as Artificial Humans, are a pivotal antagonistic force in the My Hero Academia franchise. Created by Dr. Kyudai Garaki and All For One, these bio-engineered beings are deceased humans modified to possess multiple Quirks, rendering them powerful, mindless super-soldiers for the League of Villains and later the Paranormal Liberation Front. This analysis explores the Nomu species, their various tiers, prototypes, and the unique case of Gigantomachia, a kaiju-like villain with distinct characteristics.

Nomu Species Overview

Nomu are created from human corpses, subjected to extensive genetic modification to enhance physical capabilities and implant multiple Quirks. The process erases higher brain functions, leaving most Nomu as obedient, mindless entities that require direct orders to act. Their grotesque appearance, often featuring exposed brains and unnatural skin colors (e.g., blue, yellow, black), reflects their transformation into something barely human. The Nomu serve various roles, from expendable foot soldiers to strategic game-changers in battles, with their power scaling based on their tier and Quirks.

Creation Process

Source Material: Nomu are derived from deceased humans, with some cases (e.g., Kurogiri) indicating that corpses are as viable as living subjects.

Quirk Implantation: All For One provides multiple Quirks, which are surgically integrated by Dr. Garaki. Without All For One, Garaki can still extract and duplicate Quirks, though the process is less efficient and may yield weaker results.

Modification: The transformation involves drastic physical alterations, resulting in exposed brains, jumbled internal structures, and enhanced physical attributes. The process is shrouded in mystery, with the gruesome details left ambiguous, enhancing their horror.

Purpose: Nomu are designed as tools for the League’s goals, ranging from mass destruction to targeted missions. High-End Nomu retain some personality and intelligence, tailored for specific violent tasks.

Tiers of Nomu

Nomu are categorized into five tiers based on their strength, Quirk count, and intelligence:

Lower-Tier Nomu:

Characteristics: Light-colored skin, minimal Quirks (1-2), and enhanced physical strength. They require voice commands to act and are the weakest tier, yet capable of overpowering minor Pro Heroes.

Role: Expendable foot soldiers used for overwhelming numbers or distraction.

Example Quirks: Absorption and Release, Tongue Web, Muscle Augmentation.

Notable Instances: The white-skinned Hosu Nomu with four eyes, used during the Vs. Hero Killer Arc to wreak havoc in Hosu City.

Middle-Tier Nomu:

Characteristics: More vibrant skin colors, increased power, and additional Quirks compared to Lower-Tier. They still lack significant intelligence.

Role: Stronger support units, capable of more complex tasks but still reliant on orders.

Example Quirks: Unnamed Flying Quirk, Tool Arms.

Notable Instances: The winged Hosu Nomu with a mask-like face, involved in capturing Izuku before being killed by Stain.

Upper-Tier Nomu:

Characteristics: Black skin, Super Regeneration Quirk, and strength equivalent to ten average humans. They can contend with top Pro Heroes.

Role: Heavy hitters in critical battles, often deployed to counter strong opponents.

Example Quirks: Super Regeneration, Shock Absorption.

Notable Instances: The USJ Nomu, designed to counter All Might, and the black-skinned Hosu Nomu, killed by Endeavor’s fire.

Near High-End Nomu:

Characteristics: Incomplete High-End Nomu with phenomenal strength and speed comparable to High-Ends but lacking intelligence. They were rushed into deployment, limiting their enhancements.

Role: Mass-produced for All For One’s final conquests, overwhelming through numbers and raw power.

Example Quirks: Wing, Burst, Bone Spikes, Super Spit.

Notable Instances: Deployed during the Final War Arc to support Shigaraki, with some escaping to raid Tartarus.

High-End Nomu:

Characteristics: The pinnacle of Nomu creation, with black skin, multiple Quirks (including Super Regeneration), and retained intelligence/personality. They require stabilization time post-activation to reach full potential.

Role: Strategic assets capable of independent thought and devastating combat prowess, used to shift battle tides.

Example Quirks: Super Regeneration, Liquification, Rupture, Spatial Distortion, Muscle Augmentation.

Notable Instances: Hood, Woman, Eleph, Robot, Chubs, and Ribby, deployed during the Jaku Hospital raid and Pro Hero Arc.

Powers and Abilities

Nomu exhibit a range of abilities, primarily derived from their implanted Quirks and enhanced physicality:

Common Quirks:

Super Regeneration: Allows rapid healing, even from near-total destruction, though it fails if the brain is incinerated (e.g., by Endeavor’s Hellfire).

Muscle Augmentation: Enhances physical strength, seen in Nomu like Hood and the Four-Eyed Hosu Nomu.

Shock Absorption: Absorbs impact up to a limit, as seen in the USJ Nomu.

Warping: Enables teleportation, used by utility Nomu like Johnny and Kurogiri.

Physical Enhancements: Immense strength, durability, speed, reflexes, stamina, and endurance make Nomu formidable. High-End Nomu like Hood combine these with tactical intelligence.

Weaknesses:

Brain Vulnerability: Destroying the brain is the only reliable way to kill a Nomu, as their regeneration cannot recover from this.

Command Dependency: Lower and Middle-Tier Nomu require orders, rendering them catatonic without guidance.

Stabilization Time: High-End Nomu are weaker if deployed prematurely, as seen during the Jaku Hospital raid.

Fire-Based Attacks: Endeavor’s Hellfire can overcome regeneration by reducing Nomu to ashes.

Prototypes and Key Individuals

Kurogiri

Background: Created from the corpse of Oboro Shirakumo, a former U.A. student and friend of Aizawa and Yamada. His Cloud Quirk was combined with others to form the Warp Gate Quirk.

Role: A unique Nomu designed as a loyal caretaker for Tomura Shigaraki, capable of speech and limited free thought. Unlike other Nomu, he retains personality traits (e.g., caring nature) from his human life.

Quirk: Warp Gate allows him to create portals from his foggy body, crucial for League logistics. It’s more versatile than All For One’s Glop Warp but requires his physical presence and knowledge of locations.

Key Moments:

Acts as Shigaraki’s guardian, managing his needs and preventing capture.

Defies All For One’s orders during the Final War Arc to protect Shigaraki, teleporting heroes to aid Deku and sacrificing himself to intercept an attack.

His brief re-emergence as Oboro during interrogation provides critical information about Garaki’s hospital.

Significance: Kurogiri is a prototype for intelligent Nomu, showcasing Garaki’s early success in retaining personality while programming loyalty. His eventual rebellion highlights the limits of Nomu programming when loyalty conflicts with core directives.

USJ Nomu

Background: The first Nomu introduced, designed to counter All Might as the “Anti-Symbol of Peace.” Originally a petty thug, he was modified with four extra Quirks.

Quirks: Shock Absorption, Super Regeneration, and immense physical strength.

Role: A brute force weapon, deployed during the USJ Arc to attack Class 1-A and All Might.

Key Moments:

Nearly kills Aizawa and overpowers students, showcasing its threat level.

Defeated by All Might overloading its Shock Absorption with rapid punches, leading to its arrest.

Significance: A prototype for raw power, the USJ Nomu’s limitations (e.g., inability to act without orders) informed later Nomu designs, reducing excessive modifications to preserve functionality.

Hood

Background: One of the earliest High-End Nomu, formerly a cage fighter, retaining bloodthirsty tendencies and intelligence.

Quirks: Super Regeneration, Muscle Augmentation, Shapeshifting Arm, Shoulder Jet, Storage.

Role: A test subject for Dabi during the Pro Hero Arc, deployed to fight Endeavor and Hawks in Fukuoka.

Key Moments:

Overpowers Endeavor, causing significant destruction and scarring the hero.

Uses Storage Quirk to deploy nine weaker Nomu, showcasing tactical versatility.

Killed by Endeavor’s Hellfire after Hawks’ assistance, highlighting the brain destruction weakness.

Significance: Hood represents a successful High-End prototype, balancing intelligence with overwhelming power. His rushed deployment revealed stabilization issues, a flaw addressed in later High-Ends.

Johnny and Mocha

Background: Small, utility-focused Nomu with minimal combat ability, designed for support roles.

Quirks:

Johnny: Warping, identical to All For One’s teleportation Quirk.

Mocha: Double, sampled from Twice, used to create duplicates.

Role: Facilitate League operations, with Johnny transporting members and Mocha aiding Garaki’s subterfuge.

Key Moments:

Johnny is crushed by Mirko during the Jaku Hospital raid.

Mocha sacrifices itself to protect Garaki, demonstrating unexpected initiative for a Lower-Tier Nomu.

Significance: These Nomu highlight Garaki’s versatility in creating specialized, non-combat variants, serving as early experiments in Quirk utility.

Gigantomachia

Overview

Gigantomachia is a unique entity within the League, distinct from typical Nomu due to his size, intelligence, and loyalty-driven Quirks. A kaiju-like villain, he served as All For One’s bodyguard before being assigned to Shigaraki.

Characteristics

Appearance: A gargantuan humanoid with rocky skin, spikes, and a lantern jaw, resembling a mythical giant or kaiju.

Quirks:

Endurance: Converts morale into physical power, amplifying strength when loyal to his master.

Gigantification: Allows size increase during battle.

Pain Blocker: Nullifies pain, enhancing durability.

Fierce Gains, Dog, Mole, Energy Saver: Enhance strength, tracking, burrowing, and stamina, respectively.

Intelligence: Limited (1/6 per Ultra Analysis Book), akin to a “dim-witted beast,” but capable of speech and basic reasoning. He recognizes betrayal, as seen in his rage against All For One’s abandonment.

Loyalty: Initially exhibits blind obedience to All For One, later transferring to Shigaraki after proving worthiness. His loyalty wanes after being abandoned, leading to rebellion.

Role and Key Moments

Bodyguard: Protected All For One until reassigned as a secret weapon for Shigaraki.

Meta Liberation Army Arc: Turns a losing battle into a massacre, decimating the enemy but endangering the League due to his indiscriminate destruction.

Paranormal Liberation War Arc: Bulldozes through 20 cities to reach Shigaraki, showcasing his unstoppable nature. Sedatives only work when he lacks active orders, highlighting his command dependency.

Final War Arc: Controlled by Shinso’s Quirk to fight for the heroes, leveraging his obedience to voice commands. His rage against All For One’s betrayal persists post-brainwashing, leading to his attack on his former master. Killed by All For One’s lightning attack, splitting him in half.

Impact: His destructive rampages (e.g., terrifying Mina, overwhelming Class 1-A) cement him as “pure dread” incarnate, a physical reminder of the war’s toll.

Significance

Prototype Influence: Gigantomachia’s genome informs Nomu subservience, making him a foundational prototype for their obedience programming. His multiple Quirks and physical enhancements prefigure High-End Nomu designs.

Weaknesses:

Blind Obedience: His need for commands makes him vulnerable to Shinso’s Quirk and containment when orders are absent.

Intelligence: His limited intellect allows manipulation (e.g., by Ashido) and prevents independent strategy.

Betrayal: His loyalty, while immense, has limits, as seen in his turn against All For One.

Comparison to Nomu: Unlike mindless Nomu, Gigantomachia retains some autonomy and emotional capacity (e.g., crying over Shigaraki’s weakness). His kaiju-like scale and unique Quirks set him apart, but his command-driven nature aligns with Lower-Tier Nomu.

Analysis

Evolution of Nomu Design

Early Prototypes: Kurogiri and the USJ Nomu represent initial experiments. Kurogiri prioritizes utility and intelligence, while the USJ Nomu focuses on raw power, revealing flaws like over-modification and command dependency.

Refinement: Hood and later High-Ends address these issues by balancing intelligence with power, though stabilization time remains a hurdle. Near High-Ends sacrifice intelligence for mass production, reflecting strategic shifts in All For One’s plans.

Garaki’s Role: His ability to duplicate Quirks and tweak them (e.g., enhancing Overhaul into Decay) showcases his genius, though limitations without All For One’s direct involvement highlight their partnership’s synergy.

Strategic Importance

Battlefield Impact: Nomu, especially High-End and Gigantomachia, are game-changers. Kurogiri’s Warp Gate shifts battle dynamics, while Gigantomachia’s rampages and High-Ends’ tactical prowess overwhelm heroes.

Psychological Warfare: Their grotesque appearance and relentless nature instill fear, as seen with Mina’s trauma and Class 1-A’s realization of their vulnerability post-USJ.

Countermeasures: Heroes exploit Nomu weaknesses (e.g., brain destruction, command reliance) and develop strategies like Shinso’s brainwashing to turn assets like Gigantomachia against villains.

Ethical and Narrative Implications

Moral Horror: The Nomu’s creation from human corpses, including recognizable individuals like Oboro, underscores All For One’s and Garaki’s amorality. The use of Tsubasa (potentially Garaki’s grandson) adds a personal layer of cruelty.

Redemption Potential: Kurogiri’s partial re-emergence as Oboro and Spinner’s restoration suggest that Nomu programming can be reversed, offering hope for victims but highlighting the tragedy of their transformation.

Narrative Role: Nomu escalate the series’ stakes, transitioning from school-based conflicts to existential threats. Gigantomachia’s dread and the Nomu’s relentless power embody the villains’ growing menace, pushing heroes to their limits.

Conclusion

Fates of the Nomu

The document lists specific Nomu and their statuses:

Kurogiri: Deceased, but with Oboro Shirakumo’s personality briefly re-emerging, leading to restorative research at Central Hospital to potentially reverse the Nomu process.

U.S.J. Nomu: Arrested and imprisoned, later moved to Central Hospital for restorative research.

Winged Nomu, Eyeless Nomu, Hood, Robot, Chubs, Woman, Elep, Ribby, Johnny, Mocha: Deceased.

4-Eyes Nomu, Chainsaw Nomu: Arrested.

Near High-Ends: Mixed fates, with some deceased, some arrested, and others of unknown status. Seven Near High-Ends escaped during the Paranormal Liberation War Arc and aided All For One’s Tartarus breakout, but three were later taken down, leaving four potentially active by the Final War Arc.

High-Ends: Most (e.g., Hood, Robot, Chubs, Woman, Elep, Ribby) were destroyed during the Paranormal Liberation War Arc or earlier. Five High-Ends were activated during the Jaku Hospital Raid, but all were either destroyed or neutralized.

The document also notes that with Doctor Garaki imprisoned and All For One dead, no new Nomu can be engineered. Additionally, restorative research at Central Hospital was used to save Spinner’s mind from deteriorating due to extra Quirks, suggesting a shift toward reversing or mitigating the Nomu process.

Speculation on the Nomu’s Fates

Arrested Nomu (e.g., U.S.J. Nomu, 4-Eyes Nomu, Chainsaw Nomu):

These Nomu, already in custody, are likely subjects of ongoing restorative research at Central Hospital, as mentioned in the Dark Hero Arc. The goal is to understand and potentially reverse the Nomu process, as seen with attempts to free Oboro Shirakumo from Kurogiri. By the series’ end, these Nomu may remain in secure facilities, either as research subjects or in containment if restoration fails. Given the series’ emphasis on redemption and societal rebuilding, scientists and heroes might prioritize restoring their humanity, though success is uncertain due to the complexity of the bio-engineering process. Some, like the U.S.J. Nomu, who were compliant when not under orders, might be kept in stasis or rehabilitated if their original personalities can be recovered.

Speculative Outcome: Partial success in restoring some Nomu’s cognitive functions or personalities, particularly for lower-tier Nomu with less extensive modifications. Those beyond saving would likely remain imprisoned or humanely decommissioned to prevent suffering.

Near High-Ends (Unknown Status):

The four Near High-Ends that escaped during the Tartarus breakout and survived the Final War Arc pose a significant question. The document states that all High-Ends were brought down across the battlefields, but the Near High-Ends’ mixed fates (deceased/arrested/unknown) suggest some may have survived. Without All For One’s Radio Waves Quirk to command them or Garaki to maintain them, these Nomu would likely become directionless. Their lack of independent thought (unlike High-Ends) means they’d either remain dormant, wander aimlessly, or act on residual instincts, potentially causing chaos until neutralized by heroes.

Speculative Outcome: Heroes, possibly led by figures like Best Jeanist or Lemillion, would track down and subdue these rogue Nomu. Given their strength, some might be destroyed in confrontations, while others could be captured for research or containment. The series’ focus on a hopeful future suggests efforts to prevent further destruction, so these Nomu would likely be secured or decommissioned rather than left unchecked.

High-End Nomu:

The document confirms that all active High-Ends (e.g., Hood, Robot, Chubs, Woman, Elep, Ribby) were destroyed by the end of the Paranormal Liberation War Arc or shortly after. The remaining High-Ends in stasis were likely destroyed when Tomura disintegrated parts of Garaki’s laboratory, or they were rendered non-functional without stabilization. Since no new Nomu can be created, any inactive High-Ends would remain non-operational.

Speculative Outcome: No High-End Nomu remain active post-series. Any undiscovered stasis chambers would likely be found and dismantled by heroes or authorities during cleanup operations, ensuring no future threats.

Kurogiri and Restorative Research:

Kurogiri’s case is unique due to Oboro Shirakumo’s partial re-emergence. The restorative research at Central Hospital, combined with the series’ epilogue emphasizing societal recovery, suggests a strong push to save Nomu with recoverable personalities. Kurogiri, as a High-End with advanced cognitive abilities, is a prime candidate for this. The success with Spinner indicates that medical advancements could partially reverse the mental damage caused by Quirk overloading, potentially allowing some Nomu to regain fragments of their former selves.

Speculative Outcome: Kurogiri might be partially restored to Oboro Shirakumo, though not fully, given the extensive modifications. He could live under supervision, possibly aiding heroes with his Warp Gate Quirk as a form of redemption. Other Nomu with less complex transformations might also benefit, but those with severe brain damage (e.g., Lower-Tier Nomu) may only achieve minimal recovery.

Broader Implications:

The My Hero Academia epilogue emphasizes rebuilding society and addressing the root causes of villainy. The Nomu, as victims of horrific experimentation, would likely be treated with compassion in this new era. Heroes and scientists might view them as tragic figures rather than monsters, focusing on ethical research to undo Garaki’s work. The absence of All For One and Garaki ensures no new Nomu will emerge, allowing resources to focus on containment and rehabilitation.

Public sentiment, shaped by figures like Izuku Midoriya, would likely advocate for humane treatment, especially after revelations about Nomu like Kurogiri/Oboro. This could lead to specialized facilities for Nomu, balancing security with attempts at restoration.

Factors Influencing Speculation

No New Nomu: With Garaki imprisoned and All For One dead, the Nomu production line is permanently shut down, limiting their threat to existing units.

Restorative Research: The success with Spinner and the focus on Kurogiri suggest a scientific push to reverse Nomu transformations, though the complexity of High-End and Near High-End Nomu makes full recovery unlikely.

Hero Society’s Evolution: The series ends with a focus on empathy and rehabilitation, as seen with characters like Spinner and Gentle Criminal. This ethos would extend to the Nomu, prioritizing their containment or restoration over destruction unless necessary.

Remaining Threats: The four Near High-Ends of unknown status are the primary lingering threat, but their lack of independent thought and the heroes’ vigilance make it likely they’d be neutralized post-war.

Final Speculative Scenario

The implication that the Winged Nomu (one of the three Nomu unleashed during the Hosu City incident in the Vs. Hero Killer Arc) is actually Tsubasa—Katsuki Bakugo's childhood friend and bully of Izuku Midoriya—stems from a combination of visual cues, character connections, and creator hints in My Hero Academia. While the series never explicitly states "Tsubasa was turned into the Winged Nomu" in the main storyline, it's heavily implied through subtext, bonus materials, and later revelations about Nomu creation. This has been treated as canon by the fandom and confirmed via author Kohei Horikoshi's extras, with the connection solidified in manga Chapter 259. Below, I'll break it down step by step, including the evidence, how the transformation likely occurred, and a timeline for when it might have happened.

Key Evidence Supporting the Implication

Physical Similarities and Quirk Match:

Tsubasa's Quirk is an unnamed wing ability that grants him red, draconic wings from his back, allowing flight. He's described as a plump child with a rounded face and nearly shaved brown hair.

The Winged Nomu (pale-yellow in color) has bat-like wings for flight, talons on hands and feet, and a gas mask-like covering over its mouth. While the Nomu's appearance is distorted (as all Nomu are grotesque, brain-exposed modifications), the core Quirk is identical: wings enabling aerial mobility. The Nomu's wings are its primary (and only named) Quirk, suggesting it could be the base ability from its original human form.

During the Hosu incident (Manga Chapters 50-59, Anime Episodes 28-33), the Winged Nomu specifically targets Izuku Midoriya, grabbing him and attempting to fly away with him as a hostage. This selective behavior is unusual for Nomu, who are typically mindless destroyers acting on orders. It hints at residual memories from Tsubasa's past, where he frequently bullied Izuku alongside Bakugo.

Family Connection to Nomu Creation:

Tsubasa is the grandson of "Dr. Tsubasa," the kindly doctor who diagnosed young Izuku as Quirkless in Chapter 1 (Anime Episode 1). This doctor is later revealed to be Kyudai Garaki (also known as Daruma Ujiko), All For One's mad scientist ally responsible for engineering all Nomu.

Garaki's reveal in Chapter 259 confirms his alias as Dr. Tsubasa, showing he's been operating under false identities while running hospitals and orphanages as fronts for his experiments. As Nomu creator, Garaki has access to human subjects (often criminals, the deceased, or the vulnerable), and using his own family member fits his ruthless, unethical character—he's shown no qualms about human experimentation.

Creator's Hint in Bonus Materials:

The strongest implication comes from Horikoshi's omake (bonus sketch/commentary) in My Hero Academia Volume 7. Here, the author draws Dr. Tsubasa (Garaki) alongside his unnamed grandson, who has wings identical to Tsubasa's from the flashbacks. The sketch is juxtaposed with Nomu designs, heavily suggesting the boy's fate. This is where the theory originated and was essentially "confirmed" by the creator without spoiling the main plot.

Horikoshi often uses omakes for subtle lore drops, and this one ties directly to the Hosu Nomu arc covered in that volume.

Nomu Lore and Behavioral Clues:

Nomu are bio-engineered weapons created by Garaki using All For One's Quirk-duplication tech. They start as human bases (often corpses or living subjects), which are surgically altered, infused with multiple Quirks, and have their brains reprogrammed for obedience and aggression. Lower-tier Nomu like the Winged one retain some base traits but lack higher intelligence.

The Winged Nomu's death (paralyzed and killed by Stain's Bloodcurdle Quirk after grabbing Izuku) prevents any further exploration, but its focus on Izuku implies lingering subconscious recognition from Tsubasa's bullying days.

How Garaki Likely Turned Tsubasa into the Winged Nomu

Based on established Nomu creation processes in the series (revealed progressively from the U.S.J. Arc onward, with full details in arcs like the Meta Liberation Army and Paranormal Liberation War):

Process Overview: Garaki selects a human "vessel" (body), often from the dead or those he deems expendable. He performs extensive surgeries in hidden labs (like under Jaku Hospital) to enhance durability, add Quirks via All For One's stockpiling, and expose/modify the brain for control. The result is a super-strong, Quirk-augmented monster with no free will. Early Nomu (like those in Hosu) are prototypes—less stable and with fewer added Quirks compared to high-end ones.

Specific to Tsubasa: As Garaki's grandson, Tsubasa would have been an easy target—living nearby, trusting his grandfather, and possessing a useful Quirk (wings for mobility). Garaki likely abducted or lured him, killed him (since many Nomu are confirmed to be made from corpses), and used his body as the base. The Winged Nomu has only one named Quirk (wings), suggesting minimal additions—perhaps just enhancements for strength and talons, keeping the original wings as the core feature.

Motivation: Garaki's fanaticism for All For One and Quirk research overrides family ties. He views humans as tools, and turning his grandson could have been an early experiment to test Nomu viability on someone with a flight-based Quirk. This fits Garaki's backstory as a Quirk-obsessed doctor who faked kindness while building an empire of horror.

No exact "how" details are given in canon (e.g., no scene of the surgery), as it's left to implication for shock value. It's a dark Easter egg highlighting the series' themes of abuse and lost potential.

When It Likely Happened

Timeline Context:

Tsubasa appears in flashbacks during Izuku and Bakugo's early childhood (ages 4-10, roughly elementary school), bullying Izuku and adventuring with the group (e.g., the forest incident in Chapter 1).

The text notes they "parted ways" and lost contact during middle school (ages 12-15). Izuku and Bakugo attend Aldera Junior High without Tsubasa mentioned, implying he disappeared or moved.

The Hosu incident occurs early in the main series (April-May of Izuku's first year at U.A. High, when he's 15-16).

Estimated Window: Sometime during middle school, likely 1-3 years before the series starts (around ages 12-14 for Tsubasa). This allows time for Garaki to experiment, as the Hosu Nomu are "new" but not the first prototypes (the U.S.J. Nomu predates them slightly). Garaki had been creating Nomu for years under All For One, but the Hosu trio were rushed for Tomura Shigaraki's tantrum against Stain.

If it happened post-childhood parting, it explains why Tsubasa vanishes from the story—no one questions his absence, assuming he just drifted away. The transformation must predate Hosu, as the Nomu is deployed there.

Why This Matters in the Story