A/N:

PREVIOUSLY:
Katsuki is thrown back in time, though doesn't immediately recognize so. He's now trapped in a time loop, which he's gone through twice now (or that's what he remembers, at least). The first time, he went on as he would've normally woud've except with an odd case of deja vu, while the second time he was horribly traumatized when he watched all of his friends be murdered right in front of him (yikers). The chapter ended with the start of the next loop.

anyway, updates are on tuesdays, though probably not regularly 'cause it's a complicated/long fic

It's all Katsuki can do to keep himself from flinching when he hears Izuku's voice. His head aches, as if someone had brought a jackhammer to his skull and the aftershocks were still running through hairline fractures in his bones.

"Kacchan—"

"Fine," Katsuki replies with more heat than necessary, then exhales when he feels Izuku's gaze burning into the back of his head. "I'm fine."

"...A-alright," Izuku lets out haltingly, the fight leaving him in an instant. "S-sorry, Kacchan."

He hears, rather than sees, him walking back to his desk. Despite himself, Katsuki feels a twist of disappointment in his chest.

"Not even gonna look at the guy?" Extra #1 whistles. "Damn, that's cold, Katsuki."

A sickening crack echoes throughout his mind, and Katsuki feels his mouth dry out in an instant. His tongue sticks to the roof of his mouth, unwilling to budge even after several seconds pass.

"...Hey, dude," Extra #1 eventually asks, "Are you alright?"

"You look kinda pale," Kariage points out with a frown. "Do you want us to take you to the nurse or something? She should still be here."

Katsuki exhales once again, then forces himself to look past their unseeing eyes to see the concern etched into their expressions. He expects to feel annoyance, or perhaps rage, in response to their pity, but when he feels guilt wash over him instead, he's nearly knocked off balance.

"I'm fine," he repeats, sounding distant to his own ears. Kariage presses his lips together, unconvinced, and Katsuki forces out a scoff. "I am."

He pushes himself upwards, only to nearly trip over his own feet when he attempts to take a step forwards. He barely manages to catch himself on a desk, a ragged breath escaping his lips. When one of the extras moves towards him, his grip tightens until his knuckles whiten.

"Don't," he warns them quietly, dangerously , and they both freeze. He breathes out through his nose and regains his balance. "Don't follow me," he says, heading towards the door.

He's only a few steps away when Kariage appears in front of him, blocking the way through.

Katsuki narrows his eyes, feeling a flicker of irritation in his chest. "Move."

Kariage hesitates, briefly, before a steely glint enters his eye. "No. Not until you tell us what's going on."

"We've known you for years," Extra #1 agrees. "I think we deserve that much."

Katsuki's jaw tenses. He doesn't have time for this, he thinks, only to pause when he notices the looks that both teens are sending him.

They're… concerned.

"...I'm going to find Deku," he grits out eventually, the truth rolling off his tongue about as smoothly as sandpaper.

"What?" Kariage asks, suddenly looking confused. "Why ?"

Katsuki presses his lips together, beginning to consider the benefits of simply launching himself out the window. He almost feels as if that'd be faster, in this situation. "There's just something I need to tell him."

"...Fine," Extra #1 eventually says, bringing him pause.

"Nagaku..." Kariage lets out, then glances between the two of them before stepping out of the doorway. "Alright. Just go easy on him, yeah?"

Katsuki stares at the both of them before nodding, feeling guilt stab at his chest despite himself.

(Before, he hadn't even cared to properly learn their names. What else had he missed?)

"See you," he eventually offers lamely, then steps out the door. The moment he's out of sight, he takes off in a full-on sprint. Someone, probably a teacher, yells at him on his way out, but he doesn't bother stopping.

No, this time, he runs the entire way to the tunnel and arrives feeling like his lungs have been set on fire.

"Deku!" he shouts again, and the same startled exclamations as before spill from Izuku's lips as Katsuki jerks him away from the sludge villain.

He doesn't know what's going on, except that he's either losing it or experiencing the weirdest quirk he's ever seen, but unless he wants to kick the bucket before he even graduates middle school, he has to adapt somehow.

Later, he tells himself, locking away his inevitable freak out. He shushes the gruff voice in the back of his mind - one he doesn't recognize, yet still feels similar all the same - that tells him the dangers of compartmentalization and forcibly grounds himself by digging his heels into the concrete.

"Give me your backpack," he murmurs, watching as the sludge villain reforms.

"I-is that—"

Katsuki resists the urge to curse at the green-eyed teen, wondering just how useless someone can be in a situation like this. "Now, Deku."

The sludge villain's laughter rings throughout the tunnel. A moment later, a yellow backpack is thrust roughly into his arms.

Katsuki lets out a quiet curse when it nearly topples him over, but ignores Izuku's frantic apologies in favor of unzipping the thing.

"What are— oh," Izuku lets out, eyes lighting up in understanding. "Are you sure this'll work…?"

"It fucking better," Katsuki replies curtly, not bothering to pay attention to whatever the fuck the villain is monologuing about.

Last time, the backpack by itself wasn't enough to keep him occupied. Hopefully, an assortment of school supplies would be.

He cuts off the sludge villain's words with a pencil pouch to the eye. There's a brief moment of tense silence before the sludge villain snarls, and Katsuki begins flinging things out at the asshole, adding a bit of explosive power to increase the damage. Izuku stands beside him, face pale and looking like he might pass out.

After a minute or two, he runs out of things to throw. All that's left is the backpack itself, and an innocent-looking notebook settled in the bottom.

He pauses, briefly, hand on the notebook before he huffs and thrusts it towards Izuku's chest, forcing the gawking dumbass to scramble in an effort to catch it. After seeing what it is, Izuku stares at him, wide eyes, and Katsuki averts his gaze.

It's not like one thing will make that much of a difference, he tells himself. And it's not like a notebook is a very viable throwing option, either.

(He stubbornly ignores the voices in his head telling him that there's something more to the action. Something meaningful.)

He throws the backpack itself last. This time, he puts as much power as he can into an explosion, and manages to startle everyone, including himself, with how quickly it flies outwards.

Fortunately, the hit lands, and with a lot more power than anything else he'd thrown. The sludge villain claws at his bloodshot eye and howls .

Katsuki's muscles tense, and he begins spitting out expletives when the sludge villain goes after them again, blinded by rage. He barely manages to roll out of the way of a stray tentacle, and Izuku - the useless nerd, of all people - has to ensure that he doesn't share the same fate as him in the 'previous run.'

And then, just when their stamina is running low and Izuku is practically wobbling on his feet, the sewer grate blasts outwards, and when Katsuki opens his eyes after the fierce winds die down, he sees that the sludge villain is decorating the walls.

He's barely able to keep himself from collapsing in relief when he sees All Might standing there, a grin on his face. Izuku has no such reservations and genuinely passes out, clearly overwhelmed.

His gut twists as he watches All Might packing the sludge up into a bottle, and feels like it's about to swallow itself whole when he launches off to head towards the police station, but he attributes that to the stress of the situation catching up with him.

But when he finally leaves the scene, the feeling only increases tenfold.

It spreads through his veins like a rampaging wildfire, crawling through his limbs and racing around his heart until it splinters through his brain, and—

"K-Kacchan… Are you okay?"

Katsuki feels the air leave his lungs and resists the urge to scream.

Magma slips through his veins and bubbles through his skin until his chest begins to burn. Light explosions crackle within his palms, and the sweet scent of nitroglycerin seeps into the air.

Whatever this is, it's bullshit. He survived. The extras survived. Deku survived. What fucking more could the universe ask of him?

(Was it even the universe? Or was someone just trying to torture him, hoping he'd eventually shatter?)

"Kacchan—"

Katsuki's hands slam onto the desk, and as smoke drifts upwards from charred wood, the room goes silent. He makes to shout, to scream, to rage, but when he sees everyone around him flinch, he feels the fire burn out within an instant.

"Just… shut up," he says unnecessarily, suddenly exhausted. When no one says a thing, he wipes his sweat-soaked palms on his pants and pushes himself out of his seat.

Slowly, he glides past empty desks, only pausing upon reaching Izuku's. His hero analysis notebook lies there innocently, open for the world to see.

His hand twitches.

A ghostly notebook sails through the air. He snatches it off the desk.

"K-Kacchan?" a nervous voice says from behind him.

Katsuki presses his lips together, flipping over the notebook in his hands with the beginnings of an awful idea springing forth in his mind.

One notebook for a life. That wouldn't be so bad, would it?

"Um… P-please be careful with that," Izuku says a moment later, then cringes when Katsuki turns his gaze on him.

Katsuki's eyes flick between him and the notebook. He lifts it upwards, aims towards the window, and—

("You wanna be a hero so bad? I've got a time-saving idea for you. If you think you'll have a quirk in your next life... go take a swan dive off the roof!" )

It thuds back onto the desk, his fingers having gone numb.

He presses his hand to his temple and grits his teeth as his vision flashes white with pain. There's something—

("I obtained this quirk from somebody else… No matter what, I can't tell you who, but... I swear it's true, even if it sounds like a story out of a comic book." )

Katsuki chokes on a gasp, doubling over as he presses the heels of his palms against his forehead. Voices sound out from behind him, but he can't make out a word they're saying.

("Because Deku is the name of a hero!" )

"Oh," he rasps out, feeling his legs crumple from beneath him. "Fuck."

As he falls, manic laughter echoes in his mind, slowly buried by frantic pleas. That, and the sound of—

He comes to in a room that's never seen a splash of color in its life, barely noticing the lingering buzzing in the back of his mind. Slowly, he raises an arm over his face, squinting distastefully at the pale light that illuminates the room.

"Oh, good, you're awake."

Katsuki jerks upright, grogginess cleared in an instant. "What—" he begins, only to hiss when another sharp pain shoots through his head.

"I would take a moment to wake up, if I were you," a tired-looking woman says impassively from where she's sitting at her computer. "Not that there's much wrong with you, aside from what's presumably increased stress levels. Maybe a migraine, considering that reaction you had."

Katsuki blinks. Once. Twice. "Hah?"

She looks over at him, unimpressed. "You look like you haven't slept in days, kid. And you've been sleeping there for at least half an hour now. I'm honestly surprised you weren't knocked out for longer."

"Half an hour," Katsuki echoes, then feels his stomach drop, because that means—

"You don't need to worry about your parents. They've already been informed of the situation," the nurse(?) says, completely wrong about what he's starting to panic about.

"No," he says, maybe a little too forcefully, then takes a breath. "Where are my… friends?"

"Those two boys who were sticking together went home right away," she answers easily. "The green-haired kid waited around for a few minutes before I kicked him out."

Katsuki opens his mouth, briefly, before his brows furrow.

This… doesn't make any sense. If it had been that long already, then Izuku should've—

("You looked like you needed saving!" )

His train of thoughts comes to an abrupt halt.

"Fuck."

"There's no need for that," the nurse tells him. "But if you want to leave, go ahead. There's nothing I can really do for you except suggest that you get some rest."

"Right," Katsuki lets out, already scrambling out of bed. Belatedly, he adds a breathless "Thanks," and promptly darts out the door, ignoring her halfhearted attempt to get him to stop running.

Before, he had no idea what the fuck was going on. Now, he's probably even more clueless than he was before.

He's heard about time-related quirks before, but the only one he'd encountered is Eri's, and hers… well, it couldn't have caused something like this to happen, even if she somehow managed to find herself on the battlefield. After all, her quirk allowed her to rewind people and objects - not time itself.

Briefly, he wonders if he's simply gone insane. He disregards the idea almost immediately, though, since his heart had literally exploded. There's no coming back from that without a bullshit asspull coming out of nowhere, which only occurred in fiction anyway. In other words, this couldn't be a batshit crazy fever dream, because he wouldn't be alive long enough to experience one.

But what else, then? He's decently lucky - or as lucky as someone could be, when they were attacked by villains on a regular basis as a highschooler - but not enough to be chucked back in time by the universe itself, or anything along those lines.

He can only conclude that it's the work of some sort of quirk - he just doesn't know who's.

With a scowl, Katsuki shakes his head. He can think about this later, when he has more relevant information. Now, however—

He skids to a stop in a familiar alleyway and does his best to squash the immediate sense of dread that washes over him.

It doesn't take long to spot the sludge-filled bottle now that he's looking for it. He feels relief and apprehension in equal measures, but forces himself to kick the damn thing before he can talk himself out of it.

The sludge splashes outwards, staining the asphalt. Slowly, it begins to rise, and a large, yellow eye snaps onto him.

Every one of his instincts screams at him to run away. But he can't, because stupid Izuku will never become stupid Deku if he doesn't, and he can't let that happen.

With a deep breath, Katsuki flexes his wrists and digs his heels into the ground.

Between one breath and the next, he's swallowed by hundreds of pounds of foul-smelling sludge.

The taste is acrid.

Sludge slides across his tongue, pushing back the bile that threatens to crawl up his throat. It branches out, winds around his organs, and pulls. Flames lick at the lining of his lungs, and he lurches forwards, blinking away the hot tears that prick at his eyes.

Shame settles in before fear. His hands grow hot until the air is caramelized, and his wrists jerk without conscious thought as explosions crackle within his palms. No matter how well he's trained himself, even he can't ignore the frantic alarms blaring in his head that demand him to fight to live.

Well, he'd like to tell his brain, I'd like to breathe too, but I'm a little fucking occupied at the moment.

Despite himself, Katsuki feels his hope slipping away when his limbs begin to tremble. His explosions grow more frantic, even though he can tell they're not helping in the least. His cheeks are flush with the heat, and even though he's cloaked in sludge, he can feel sweat gathering on his skin.

But Deku is (and always has been) an overdramatic bitch with a terrible sense of timing, and just as he feels fog creeping through the cracks in his mind, he's able to choke down a mouthful of air.

"KACCHAN!" Izuku shouts desperately, and if he weren't trying to ensure his survival, Katsuki would've barked out a hysterical laugh at his sudden feeling of deja vu.

"You idiot," he breathes out anyway, lightheaded as all hell.

"P-probably," Izuku agrees, tears dripping down his cheeks as-per-usual, "But you looked like you needed saving!"

Katsuki rolls his eyes on instinct, simultaneously taking in one last gulp of air before his lips are once again sealed with sludge.

This time around, he manages to keep his eyes on Izuku the entire time. He feels a spike of fear when a tentacle latches onto the green-eyed teen's arm, then a wave of relief when All Might appears next to him with a burst of speed.

"The lesson I left you with… I should practice what I preach!" the man calls out, blood spurting from his mouth. "A pro should always be ready to risk his life!"

Katsuki wonders if this conversation happened before. Probably. Kinda fucked up that they'd just have a nice chat while he's literally dying, but whatever.

"Detroit," All Might begins, which Katsuki only has a moment to process with an oh, fuck , before the latter half of the phrase is paired with a superpowered punch. "SMASH!"

Son of a bitch, Katsuki thinks as he begins flying backwards along with the villain. Fortunately, All Might manages to grab onto him before his head cracks open on the concrete, and he's slowly lowered to the ground, sweat washing away with the light rain.

Katsuki takes a breath, ensures that neither he nor Izuku have any life-threatening injuries with a glance, and promptly spews out an awful mixture of sludge and vomit onto the ground.

The cheers around them die down slightly at that, and All Might's expression spasms in an interesting way, which are both minor sources of amusement for Katsuki in this hellish situation.

His amusement dims, though, when half a dozen heroes begin to fret over him, while several others offer useless internships. He wonders if any of them even realize that they're blocking the medical team from getting anywhere near him. For all they know, he could still be at risk of dying at any moment, and yet here they were, hanging around him like limpets without a care in the world.

By the time that Katsuki's finally cleared to leave, Izuku is long gone. Just as he steps out of the alleyway to follow after him, his phone buzzes. His mother's caller ID flashes back at him, and all at once, he feels exhaustion settle into his bones.

He blows out a long breath, turns towards the direction of his house, and answers the call.

A/N:

i desperately hope this progression wasn't too fast, bc that'd be horribly cringe :)
(and before any assumptions are made... this is not the end for the time loopiness, i'm just taking a uhhhh different approach :D)

anyway
Thanks for reading!