The vault door hissed shut behind Izuku Midoriya like the seal on a tomb, cutting off the distant symphony of chaos above.
The room was a cathedral of clinical horror: walls tiled in sterile white, veined with conduits humming quirk-suppressant fields; surgical lights casting long shadows over counters cluttered with vials of shimmering serum, syringes glinting like fangs, monitors beeping a monotonous dirge of stolen lives.
In the center, the glass enclosure loomed—a cylindrical prison of reinforced plexiglass, fogged with condensation, tubes snaking from its ports to a cluster of life-support machines.
Inside, Eri huddled: small, silver-haired, her tiny horn a jagged crown of trauma, red eyes wide and glassy with exhaustion and fear.
She was strapped to a padded table, IV lines piercing her arms, her whimpers muffled by the barrier.
Kai Chisaki—Overhaul—stood before the enclosure like a surgeon at his altar, gloved hands poised mid-gesture, plague doctor's mask turning with predatory slowness.
His gray eyes gleamed behind tinted lenses, suit immaculate despite the underground grime, auburn hair slicked back in perfect order.
The air around him thrummed with latent power: Overhaul, the quirk that deconstructed and reconstructed matter at a touch—flesh to dust, dust to spikes, bodies to obedient puppets.
He had been extracting from Eri, drawing her Rewind quirk into bullet casings stacked on a nearby tray, each one a promise of quirkless subjugation.
The yakuza boss tilted his head, mask's beak catching the light like a scythe. "A child," he murmured, voice smooth as polished obsidian, laced with disdain.
"U.A.'s green prodigy, skulking in my halls like a rat. I expected Sir Nighteye. Or perhaps that golden boy, Lemillion. But you... Midoriya, is it? How disappointing"
Izuku's boots echoed once as he stepped forward, green eyes locked on Chisaki, Ocean mapping the man's steady pulse—no fear, only calculation.
The army's distraction raged above: Earth Titan's roars shaking the foundations, Muscular's bellows mingling with skeletal clashes, Gasper's time-stops freezing patrols in amber.
Eri's heartbeat fluttered erratic through the glass, a fragile drum against his senses. Rage coiled in Izuku's chest, hot and human, Power baseline in his fists—ready to forge into thunder.
"You're done here, Chisaki," Izuku said, voice low, edged with the steel of a hundred rewritten fates. "Eri comes with me. Now."
Overhaul chuckled, a dry rasp behind the mask. "Bold words from a boy playing hero. You think your little diversion upstairs buys you time? My Eight Bullets are already converging. And this girl..." He gestured languidly to Eri, who whimpered, curling tighter. "She is the cornerstone of a new world. Quirkless purity. A reset for society's filth. You, intruder, are merely an inconvenience."
Eri's eyes met Izuku's through the glass—pleading, broken. Something snapped in him.
Izuku moved.
Chisaki was fast—Overhaul activating in a blur, right hand touching the floor. The tiles erupted: ground disassembling into a spike of jagged rebar and concrete shards, lancing toward Izuku like a venomous bloom.
It was surgical, lethal—matter unmade and remade in an instant, aimed to impale and pulverize.
Izuku twisted, baseline human speed carrying him left—the spike grazing his shoulder, tearing fabric and drawing a hot line of blood.
Pain flared, but he was inside Chisaki's guard, fist arcing in a straight jab to the jaw.
Thud.
The first hit landed clean—Power igniting, scaling from zero to one.
Chisaki's head snapped back, mask cracking along the beak, but Overhaul surged: left hand slamming Izuku's chest.
Flesh and bone shifted—Izuku's sternum disassembling into a spray of blood and pulverized calcium, ribs unmaking in a wet crunch.
Agony exploded, white-hot and intimate, Izuku's body folding as he hit the wall ten feet back, sliding down in a smear of red.
The class's cheers from the exhibition felt distant; this was no spar. Chisaki advanced, gloved hands flexing, the floor rippling under his steps like living skin.
"Pathetic. Children with dreams of glory, always breaking so easily."
Eri screamed, muffled: "Stop! Please!"
Izuku coughed blood, vision tunneling, but Power hummed—untapped, waiting.
Human limits screamed, lungs collapsing, heart stuttering. Chisaki loomed, right hand raised to finish: touch the skull, unmake the brain, reconstruct a trophy.
Izuku rolled.
The touch grazed air; Izuku surged up, shoulder-checking Chisaki's midsection—thump, two—driving the yakuza back a step.
Chisaki snarled, Overhaul flaring: spikes from the wall, coiling like serpents to ensnare.
Izuku ducked one, felt another rake his thigh—fabric shredding, muscle parting in fire—but countered with a hook to the ribs—crack, three—Chisaki grunting as bone gave slightly.
"Insolent—" Chisaki spun, disassembling his own jacket into dust, reforming it as a swarm of razor shards.
They hurled like a blender's gale, slicing air. Izuku weaved through the storm—gashes opening on arms, cheek, a deep furrow across his back—but closed again: uppercut to the chin—snap, four—mask fully shattered, revealing Chisaki's scarred face twisted in fury.
"You dare—?!" Overhaul at full: the floor erupted, tiles unmaking into a tidal wave of debris—rebar spears, concrete fists, glass shrapnel—all converging to crush Izuku into paste.
He met it headlong. Fists blurred: five shattering a spear, six pulverizing a chunk, seven—an overhead smash that parted the wave like a plow through soil.
Scaling accelerated—eight, nine, ten—each punch a detonation, shockwaves rippling back to batter Chisaki. The yakuza staggered, blood trickling from his lip, but reformed the assault: flesh of his own arm disassembling into spikes, lancing from his body like a porcupine's rage.
Izuku tanked three—piercing shoulder, thigh, grazing temple—blood sheeting hot, vision blurring red—but twenty cracked the final spike, twenty-one—a straight to Chisaki's solar plexus that caved ribs, air evacuating in a wheeze.
Chisaki reeled, mask shards crunching underfoot. "Impossible... you're not even using a quirk!"
Overhaul desperation: he touched his own wounds, reconstructing flesh in grotesque bulges—spikes protruding from shoulders, arms elongating into bladed whips.
The room warped, walls unmaking into grasping hands of stone, ceiling raining debris.
Izuku became the storm's heart. Pain was fuel—gashes burning, blood slicking grip—but Power escalated unchecked: thirty shattering a stone hand, thirty-five pulverizing a whip arm, forty—a haymaker that shattered Chisaki's reconstructed spikes, shards exploding inward to lacerate the yakuza's own body.
Chisaki screamed, Overhaul faltering—matter obeying sluggishly, wounds reopening as focus cracked.
"You... child... I'll unmake you atom by atom!" Chisaki lunged, hands glowing: touch to disassemble Izuku's heart.
Izuku sidestepped, counter-hook to the elbow—boom, fifty—joint exploding in wet crunch, arm dangling useless.
Chisaki howled, left hand reforming it in bubbling mass, but Izuku was relentless: knee to the gut—fifty-five—doubling him; elbow to the spine—sixty—vertebrae grinding; uppercut to the throat—sixty-five—Chisaki gagging, blood foaming.
The yakuza collapsed to knees, Overhaul sputtering: floor rippling weakly, spikes forming as nubs. "This... isn't... possible..."
Izuku loomed, chest heaving, body a roadmap of wounds—gashes weeping, ribs cracked anew, blood pooling at boots. But his fist raised, Power at seventy, humming like a reactor. "For Eri. For every kid you broke. This ends."
The final punch—a straight, world-ending cross—connected clean to Chisaki's jaw. KABOOM.
Chisaki's head whipped; teeth shattered; neck snapped back with force that cratered the wall behind.
Overhaul died in the instant—quirk fizzling, body crumpling like discarded refuse, unconscious in a heap of his own blood and broken pride. The room stilled, monitors flatlining, debris settling in hush.
Izuku sagged, vision swimming, but Eri's cry anchored him. He staggered to the enclosure, palm slamming the release—tubes hissing free, glass sliding open. Eri uncurled, trembling, eyes locked on him like salvation incarnate.
"You're safe," he rasped, scooping her fragile form—light as a bird, warm despite the chill. She buried her face in his chest, sobs wracking her. "No one's hurting you again."
But safety demanded more. Chisaki's Eight Bullets converged—footsteps thundering from halls, quirks igniting. Eri in arms, Izuku's free hand delved the pouch: two Master Balls, cold absolutes.
First: Chisaki's limp form. Izuku pressed the sphere to the yakuza's forehead—red light blooming, body dissolving into energy, sucked inexorable.
The ball snapped shut, warm in his palm. Overhaul: contained, obedient, a weapon turned tool.
Second: Eri, still clutched close. Her eyes widened—fear flashing—but Izuku whispered, "Trust me. Just for now. To keep you safe."
The ball touched her brow; she didn't fight, light enveloping gentle. Captured. Safe. Rewind's power sealed loyal, away from prying hands.
Pouch secured, Izuku bolted—Power reset, body screaming limits, but will iron. Halls swarmed: Eight Bullets charging—Chronostasis with arrow clocks, Mimic with contorting flesh, Shin with rifle-barrels from fingers.
Izuku met them in frenzy. Baseline surge: punch to Chronostasis's knee—thud, one—dropping him; elbow to Mimic's twisting arm—crack, two—flesh locking malformed.
Shin fired quirk-bullets; Izuku dodged, counter-hook crumpling the barrel-hand—boom, three.
They pressed: time-arrows slowing him (one grazed, seconds dragging), Mimic elongating to snare, Shin's volley chaining lightning.
Izuku scaled through hell—five shattering an arrow, ten pulverizing Mimic's limb, fifteen—a haymaker to Shin's chest cratering ribs.
Deeper levels evacuated under the Titan's siege above—Muscular's roars, Gasper's shadows, thralls clashing in endless tide.
Izuku burst to the loading dock, army holding the line: Titan swatting choppers like flies, Muscular bulldozing reinforcements, skeletons reforming in green haze, Gasper's Balor freezing squads mid-charge.
"Enough!" Izuku commanded, voice thunder. Necromantic sigils flared; the rift yawned.
Servants streamed back: Gasper folding wings into void, thralls collapsing to bone-stacks, Muscular bellowing a salute before vanishing, Titan shrinking to storage with a ground-shaking stomp.
The HQ shuddered—pillars cracking under Titan's parting gift. Yakuza faltered, chaos cresting.
Izuku sprinted for the sewer grate, Eri's ball clutched like a heartbeat.
Alarms wailed; spotlights swept—but he was smoke, vanishing into the underbelly as the fortress crumbled behind.
He ate a senzu bean which restored him back to full health.
The night swallowed him whole.