Chapter Text
The cries of the audience thundered through the underground arena, shaking the walls and rattling through Izuku’s ears as he waited behind the iron gate.
His friends stood by his side.
Thankfully, today the Ring Masters had allowed Himiko and Hitoshi to wait with him before the match. Their conversations always made the fear easier to bear. Looking back, Izuku wasn't sure how he had survived the many lonely months before they had arrived.
"Are you sure you don't want one of my knives?" Himiko asked, absentmindedly twirling a strand of her blond hair around her deft fingers. "I mean... Hitoshi says they're really easy to use."
Beside her, Hitoshi nodded. "They are," he said simply. "And if you end the fight fast, they won’t get a chance to hurt you."
Izuku shook his head. As tempting as it was, he couldn't bring himself to use such lethal weapons—not unless he had absolutely no other choice.
"I'll be okay," he assured them with a small smile.
Himiko clenched her fists beneath her chin. "You can do this, Zuku!" she said earnestly before glancing towards the roaring crowd. "Besides..." A small smile spread across her face. "You said it yourself—you haven't lost in forever!"
Himiko was only trying to encourage him, but the reminder of his winning streak did little to comfort him. If anything, it only made the knot in his stomach tighten more: losing meant disappointing his handler.
People always bet on Izuku to win, and every victory brought in a share of the betting profits. More betting meant more sponsor donations. More sponsor donations meant higher stakes.
A broken winning streak would cost his handler money, and Izuku knew exactly how that kind of disappointment was punished—the angry scars on his back were proof of that.
Still, Izuku gave his friends a small nod, hoping it would reassure them more than himself. Then, with practiced motions, he adjusted the cloth respirator over his face before pulling the hood of his black hoodie a little lower.
"And now!" the Ringmaster bellowed from the observer booth high above. His domino mask concealed his eyes, but his broad grin was more than enough to animate his performance. "The one you've all been waiting for! You've seen him overcome impossible odds! You've seen him paint this arena red! You know him! You love him! Give a round of applause for... Needler!"
The crowd erupted.
Beside him, Hitoshi and Himiko exchanged uneasy glances before swallowing hard. They both knew the truth behind the cheers: Izuku fought more often than either of them—leaving him exhausted long before most matches even began.
"Good luck," they whispered together.
Izuku looked at them both, giving them a thumbs up, before stepping into the arena. Instantly, he was bombarded by a sight he had long since come to despise.
Hundreds of spectators crowded the caged pit, shoulder to shoulder behind rusted fencing. Their cheers merged into a deafening roar as they pounded on the metal rails, stomped their feet, and shouted through heavy respirator masks that hid every face—reducing them to little more than anonymous eyes staring hungrily into the cage.
The Ringmaster spread his arms wide, soaking in the crowd's anticipation.
"And now... a new challenger!" he hollered. "A lover of blood, gore, and violence! The monstrous brute! The villain who slaughters heroes... Muscular!"
On the opposite side of the arena, the iron gate rattled open.
A towering man strode into the cage.
The man had opted to wear a clear respirator mask—giving Izuku a clear view of his every expression: a sure intimidation tactic.
He looked to be in his early twenties, with broad shoulders, thick muscles, and a mess of unkempt blond hair. His black eyes were cold—almost feral—and a wide grin stretched across his face as he cracked his knuckles and rolled his shoulders, looking far too excited.
He was massive.
Seriously?
Ever since he had turned thirteen, Izuku couldn't shake the feeling that the Ring Masters enjoyed throwing him into fights he had no business surviving.
”Killer of heroes.”
The title should have terrified him; instead, Izuku felt... nothing.
Somewhere along the way, he had stopped allowing himself to feel fear.
Fear meant shaky hands. Fear meant hesitation. Overall, fear meant mistakes—and mistakes got you killed.
If anything, the title only strengthened his resolve.
So, rather than shrinking back, Izuku tightened the straps of his respirator and stood tall.
The two opponents faced one another in the center of the arena while the referee stepped between them.
"The rules are simple," he announced. "The match ends when one fighter submits... or is rendered unconscious."
"Boo..." Muscular groaned dramatically, dragging out the word. "I was hoping to kill the brat." A cruel grin spread across his face. "Why not make it a death match?"
A chill crept down Izuku's spine.
Thankfully, even the Ring Masters drew a line somewhere: children weren't allowed to compete in death matches.
Still… that didn't mean he was safe.
Muscular could still shatter every bone in Izuku's body if he wanted to. As long as he survived, The Nurse could put him back together afterwards. His owners didn't care how badly he was broken—as long as he could fight again.
"Death matches involving minors are prohibited," the referee replied flatly.
Muscular exaggerated a disappointed pout before shrugging. "Oh well." His grin returned, wider than before. "Accidents happen."
His black eyes locked onto Izuku's. Every instinct in Izuku screamed that the threat was genuine.
"Take your places."
The fighters moved to opposite ends of the arena.
"Ready!"
Izuku slid two steel drift pins into his hands, settling into his usual fighting stance as he tightened his grip. Across from him, Muscular simply rolled his shoulders and cracked his neck, smiling eagerly.
The referee raised the red flag.
"Go!"
The instant the flag dropped, Muscular exploded into motion: he charged without a moment's hesitation.
Thick strands of crimson muscle burst from beneath his skin, coiling around his arms like living ropes. They swelled with terrifying speed, transforming his already massive limbs into something downright monstrous.
Izuku barely had time to pivot away from the attack.
The punch screamed past his face. The force of it alone sent a gust of air across the arena, making the concrete behind him explode.
Chunks of stone showered the ring, and the audience erupted in vicious, excited roars.
"Did you see that?!” Ringleader questioned the audience. “He almost took the kid's head off!"
Despite the rumbling around him, Izuku’s eyes never left Muscular: he couldn’t afford to get distracted.
The villain’s muscle fibers...weren't normal.
They shifted above the skin like living ropes, tightening together just before each strike.
Muscular laughed, obviously having the time of his life. "Quit running!" he exclaimed just before lunging again.
Izuku ducked beneath another punch before spinning around the villain's side. He shot his drift pin towards the pressure point beneath Muscular's shoulder and struck.
Then… there was nothing.
Izuku's eyes widened in astonishment: he knew the blow had landed, yet Muscular’s arm didn’t weaken; instead, the muscle hardened like tensing steel cables.
Muscular's grin widened. "That tickles,” he mocked.
His elbow came crashing backwards, and Izuku barely managed to throw himself aside; it smashed into the ground where his ribs had been a heartbeat earlier.
The arena floor cracked as Izuku rolled across the concrete before springing back to his feet.
Why hadn’t his attack worked? Why was Muscular still standing in perfect condition?
The villain flexed, causing the swollen muscles around his shoulders to shift again.
Understanding suddenly flashed through Izuku's mind: Muscular’s many muscle fibers were protecting his nerves…So, the quirk wasn't merely making Muscular stronger, but it was changing his anatomy as well!
The muscle bundles were repositioning themselves around vital areas. Thus, his normal pressure points weren't where they should have been.
Somehow, the realization sent just as much excitement as it did horror through Izuku’s body. His adrenaline spiked.
Muscular’s body was rewriting his defenses—adapting. He’d be a difficult opponent to face.
The villain burst into laughter. "You're thinking. Aren’t you?" He pointed at Izuku with one massive finger. "I can always tell. You little fighters are always thinking!”
With a shake of his head, he slammed both his fists together. "I don’t! I just use my muscles to break things!"
Then, he charged, howling as he approached Izuku.
Instead of retreating, he gracefully slipped inside Muscular's reach. His drift pins danced across the villain’s torso: LU-1, LI-15, SJ-14…
Each strike lasted less than the blink of an eye.
Then, he drove the rods into the groove beneath the clavicle, skimmed the insertion of the deltoid, and hammered the musculocutaneous nerve where it emerged between the biceps and brachialis.
Izuku jumped back, letting his feet slide against the arena pavement. He watched Muscular with a critical eye.
On a normal person, the sequence would have left the arms numb for several precious seconds, but Muscular… seemed fine.
Muscular laughed right in Izuku's face. "What're those little pokes supposed to—"
He stopped as the muscle fibers detached from their distal anchor points, slumping to the ground in limp, ribbon-like bundles that still hung from his body.
Instantly, his grin disappeared. "Hm?"
Izuku glared, allowing himself the smallest flicker of triumph: he had found an opening—not a true pressure point, but a place where Muscular's enlarged muscle fibers couldn't completely shield the nerves beneath.
The audience erupted.
"What the hell?!" Ringleader exclaimed, seemingly on the edge of his seat. "He knocked his quirk off!"
Muscular stared at his lax muscle fibers in disbelief before experimentally lifting his arm. "Weird,” he huffed, sounding both amused and annoyed.
His right arm trembled—but only enough to make him hesitate.
Still, Izuku didn't waste the opportunity: he leaped forward, letting his drift pins flash.
One hit struck the inside of Muscular's elbow with a loud crack. Another clipped the side of his neck. A third strike hammered into the floating ribs.
Muscular grunted as another bundle of muscle peeled away from his torso. “Tch…” he tsked, frustrated, as he stumbled half a step.
Izuku circled behind him, refusing to stay in one place—lest the villain manage to grab him.
Muscular swung blindly. His fist carved through empty air. Even without the full power of his quirk, he nearly managed to throw Izuku off his feet.
Izuku recovered with a roll of his heels and attacked low, driving another precise strike towards the villain's knee.
The muscle there detached too, and for the briefest moment, Muscular's stance faltered.
The arena fell strangely quiet: even the gamblers among the crowd seemed stunned to see the Needler winning
Then, suddenly, a wet sound echoed through the arena.
Izuku's eyes widened.
The detached muscle fibers dangling around several points of Muscular’s arms twitched. They crawled up the stone floor, lifting like living metal wires using static to pull themselves back into place.
The loose bundles wrapped themselves around his bicep once more and knitted together layer by layer—thicker and denser.
Within seconds, Muscular’s arms looked exactly as they had before. He rolled his shoulders with an audible pop.
His laughter started low. Then, it grew louder as he flexed. "So that's what you were trying to do,” he exclaimed, amused.
The compliment sent a chill through Izuku: not because Muscular was smiling with mockery—but because he was smiling with understanding.
His grin widened until it looked almost inhuman. "You found a blindspot, but..." The muscles across his chest began shifting as he spoke.
Izuku froze. He watched in horror as newly grown fibers settled over the exact nerves he had targeted moments earlier.
"That won't fool me twice."
Izuku's heart skipped: Muscular was adapting.
Every pressure point he had figured out—every weakness…Muscular was literally growing armor over all of it.
"So... " Muscular taunted as he lowered himself into a runner's stance. "Let's see how many weak spots you've got left to find."
The concrete beneath his feet exploded, as this time he ran twice as fast.
Izuku barely managed to duck as Muscular's fist tore through the space where his head had been.
The impact struck the arena wall instead. Stone burst outward in a cloud of dust, and cracks spiderwebbed across the rock.
The fight had become exactly what Izuku had dreaded—a race between his analysis and Muscular's ever-changing anatomy.
The crowd roared in anticipation.
Despite the adrenaline racing through his veins, Izuku exhaled slowly as he moved: his heartbeat steadied, and his breathing slowed. He needed to focus.
Every lesson his mother had ever taught him; every observation written in hundreds of Grandma Shuzenji’s notebooks; every correction from Ojiro Sensei; every brawl with Katsuki; every acrobatics class shared with Mashirao and Itsuka; every training session with Aizawa Sensei; and every weapons lesson with Himiko and Hitoshi… they all flashed through his mind in rapid succession.
He darted left the instant Muscular's fist crashed into the stone behind him. He slid beneath the villain's sweeping arm, his drift pins flashing once more.
One strike landed just above the kneecap at acupoint ST-35, while another snapped into the inside of Muscular's wrist along PC-6 on the median nerve.
Muscular staggered, and some of his muscles slipped off—but only for an instant.
Within seconds, the detached muscle bundles slithered back into place before Izuku's eyes.
"Seriously?" Izuku muttered beneath his mask.
He couldn't keep doing this: every weakness disappeared almost as soon as he discovered it.
Muscular laughed loudly enough to drown out the audience. "Ha! This is fun!" he exclaimed as he swung again.
Izuku vaulted over the man’s arm, planted one foot against his shoulder, and flipped over his back.
His drift pin struck behind the ear, around point GB-20, but the muscle there had already thickened: the tip of the rod bounced off harmlessly.
"Damn," Izuku growled under his breath—frustration and panic twisting together in his chest.
He landed in a crouch and immediately sprinted away.
The arena erupted as Muscular barreled after him.
Izuku didn't look back.
Muscular jumped and threw a punch, but it met concrete instead of flesh—too slow.
Izuku pivoted around, swinging a round house kick that made contact with Muscular’s cheek. A sickening crack filled the air as the villain howled for a beat.
Then, Muscular retaliated with a quick shoulder tackle, followed by another series of kicks and punches for Izuku to dodge.
Muscular had settled into a rhythm: he favored his right side after throwing a hook, his left foot planted harder before every lunge...
His shoulders tensed a split second before he reached for a grab.
Once he saw the opening, Izuku slipped beneath the villain's arm in the blink of an eye. His drift pin cracked into the base of the villain’s ribs around the intercostal nerve at LV-13, while another clipped the inside of his thigh at LV-10.
For a moment, Izuku thought he had finally managed to injure the brute.
But then…Muscular smiled. "Gotcha."
Izuku's stomach dropped.
He had expected another strike; instead, Muscular opened his enormous arms wide.
Before Izuku could redirect his momentum, the villain stepped forward and wrapped both limbs around him in a crushing bear hug.
The world lurched, as Izuku's feet left the ground.
Muscular's laughter rumbled through his chest. "I figured it out,” he said. "You always dodge towards an opponent once you've learned their patterns."
Muscular squeezed Izuku even harder in his lethal embrace—grinning all the while. Izuku grit his teeth in agony. He swung his legs, aimlessly trying to hit something to get the villain to release his hold on him.
But Muscular’s arms simply wrapped tighter and tighter, until…something snapped.
Instantly, a wave of pain had Izuku screaming bloody murder. All Muscular did was laugh at his agony.
The referee's whistle shrieked through the arena—signaling for Muscular to stop.
But the villain only turned his head, fixing him with a cold, threatening glare. The referee froze, his hand slowly lowering as he fell silent.
The crowd erupted into chaos.
The reactions came in waves. Some spectators screamed in outrage, calling the fight a "Disgraceful display." Others—villains with some odd sense of honor—demanded that Muscular "Let the kid go!"
But just as many cheered: they roared for more blood. A few voices even screamed, "Kill him!"
Soon enough, Izuku could barely hear them anymore—as the ringing in his ears overwhelmed all the voices around him.
He continued to struggle weakly against Muscular's grip—his body still screaming in pain.
"Damn, I love seeing the life drain from their eyes!" the villain gleefully exclaimed between laughs.
Then came another sickening snap.
Izuku's breath caught.
His back…
He opened his mouth and let out a choked, broken croak of a scream. He tried to surrender—even though he knew Muscular wouldn’t listen—but he couldn’t even find the air to speak.
The ringing in his ears only grew louder.
He was going to die.
Yet, despite his drifting consciousness, a far-off and familiar voice reached him.
“Use your head!” Himiko wailed at the top of her lungs.
And, for a single moment, Izuku found himself coherent again.
How could Izuku use his head? He could barely breath! Unless…
Realization suddenly struck him. Instantly, he snapped his neck forward and bashed his skull against Muscular’s thick forehead as hard as he could.
The impact sent the villain reeling, immediately loosening his grip while groaning in pain.
With trembling arms, Izuku forced himself to move. He lifted his hand as high as his battered body allowed and drove his drift pin upward, striking Muscular's left eye.
Izuku pulled it back, letting blood and viscera slide off his weapon.
With an agonized scream, Muscular released Izuku, and the boy collapsed onto the arena floor like a discarded rag. His back slammed against the ground, sending a fresh wave of pain through his already crippled body.
Izuku could barely breathe. Each inhale came out as a ragged gasp. Each cough teared at his chest. Still, he forced his eyes open, watching through blurry vision as Muscular clutched his injured eye with both hands.
The villain screamed and stumbled, completely consumed by the pain. His balance faltered as he wobbled this way and that.
He wailed and wailed for what felt like hours until—finally—with a heavy thud, Muscular crashed onto his back. A cloud of dust erupted around him, briefly swallowing his massive frame before slowly settling back onto the arena floor.
The audience fell completely silent.
Izuku couldn't move anymore. His nerves were so relieved that his body had simply given up. A weak, exhausted laugh escaped him. "Accidents happen... bastard," he muttered.
Then, his vision blurred, and the last thing he heard was the Ringmaster's voice echoing through the arena: "And it looks like we have a tie!"
The crowd erupted.