Archive of Our Own

Katsuki’s not sure what happened.

One minute, he was patrolling the streets with Deku. The next, there’s an explosion to their right, in the department store building.

He remembers that much, but he doesn’t remember how he ended up on top of a car on the other side of the road. Alright, time to take stock.

What were you doing before you lost consciousness? Easy, patrolling.

What caused the unconsciousness? Probably the explosion, but maybe a quirk.

How long were you out? The building hasn’t burned down yet – in fact it’s only just caught. A few minutes, at most.

Can you move? Katsuki flexes his hand. It feels good, if a little sore. He rolls his shoulder, shifts his leg. He doesn’t notice anything grossly incorrect about the way he’s moving, so he concludes he’s fine.

Katsuki grunts as he pushes himself to a sitting position on the car, then stands on the ground.

That’s when he sees it.

Across the road, on the pavement right next to the building that would likely come down within minutes (especially if it gets hit again), is himself. His own body, rolled over and faced away from him, unmoving.

No fucking way did a tiny ass bomb like that kill his sorry ass.

He reaches up to his ear to call for backup. He thought he’d had a handle for the situation, but if he’s not even in his body , then they have a problem. Setting aside the fact that if he is having an out-of-body experience, he won’t be able to call anyone, he tries anyway. He fumbles when he doesn’t feel his hearing aids.

It’s only then that he notices how loud everything is, even without them. He looks at his hand as his pager rings, and finds a familiar white glove.

Fuck.

The pager dials. “This is prohero Deku requesting immediate backup at xxxx street in xxxxxxx,” he says, and Deku’s voice comes out of his mouth. “There was an explosion and the building needs to be evacuated. Potential villain at large.” He knows there is, considering he’s no longer in his own body. That shit doesn’t just happen.

It’s like learning to walk all over again. He feels clumsy and uncoordinated – Deku is heavier and bulkier than him in adulthood and he can feel every extra kilogram as he stumbles his way towards his own body as Hawks flies in overhead, arriving in seconds from when he’s called.

It’s just as well. Katsuki doesn’t think he can fight like this, even if he knew how to use Deku’s multitude of quirks.

He crouches on one knee by his own body and reaches out to shake it, reaching too high initially, expecting the weight of his gauntlets he’d been wearing all day. His arms feel so incredibly light without them, as if lifted up by helium balloons. He always gets this feeling at the end of the day when he gets out of costume, but never on shift .

His own body stirs, blinks, rolls over, blinks again, then his eyes go wide with a fear he recognises far too well. Somewhere close, a child is crying. Even over all the panic of people trying to evacuate the building and others babbling thanks at Hawks for getting them out from the upper levels, he can hear her. That’s priority two.

Priority one is making sure damn Deku can hold his shit together.

“We got swapped,” he says, and the grit he’s used to hearing with his own voice sounds strange with Deku’s. He grabs Deku’s (his own ) arm, bringing the gauntlet up to show him. Deku catches on quick. He nods, face determined, and looks around to take stock of their situation.

“You called for backup?” He asks as he stands, much more carefully than normal, and Katsuki can’t help but think it’s just a little bit funny that he’s struggling in the same way for the opposite reason. Damn, he needs to put on weight. Katsuki nods.

“Hawks is evacuating the building for us.”

The hero in question hovers to a stop above them, wings blowing both their hair back from their faces. Katsuki had recently talked Deku into letting him give him an undercut, and it was doing him favours when Katsuki was looking at him, but now it just feels a little bit chilly. “You guys alright? You don’t look hurt.”

“Did you see any villains?” Deku asks with Katsuki’s voice, and fuck , is this really what he sounds like to the nerd? He sounds so much deeper to himself. Hawks nods towards the end of the street where he has a man pinned to the ground by an arsenal of crimson feathers. “We’ve swapped bodies,” he explains quickly. Time is of the essence, even though the guy’s already been captured.

Hawks shakes his head as he lands in front of the hero duo. “No dice,” he says. “Guy let off an explosion. Unless he’s got multiples, wasn’t him.”

“I’ll talk to him,” Katsuki says, and Deku scrunches up his face in worry as he quickly conditions,

“No quirks! Just in case.” It’s a fair call – they don’t know if their quirks transferred with their bodies, but it still makes him tsk. Whatever. He doesn’t need quirks. Damn Deku’s reputation precedes him, and the man is already shaking in his likely stolen boots as Katsuki stomps on over to him.

“Oi, dickhead,” he says, remembering too late that Deku doesn’t fucking curse. He cringes internally, knowing he’s going to get his ass handed to him later for it, but doesn’t back down. “What’s your quirk? Start talkin’ or I start smashin’.” Threats. Another thing Deku does not incorporate into his interrogation routine.

“B-b-bombs!” He offers with no resistance at all. “I make bombs from my h-hair!” Said hair is brown, and chopped roughly in multiple places. The explanation checks out.

“Is that all?” Katsuki presses, crouching down to his level so if he lifted his chin, he could see the wild look in Deku’s eyes, daring him to lie.

“Yes, yes that’s all!” He cries, actually sobs, and Katsuki wonders how someone as pathetic as this managed to bomb a fucking building. It’s embarrassing, to have to clean up this mess, and to have to call help to do it. Oh, he is not looking forward to the paperwork for this one.

He flips the man the bird for good measure as he jogs back over to where Hawks is cradling a crying girl. Must have been the one he heard before. She’s reduced to sniffles, now, but Deku is keeping a notable distance, and begins talking to one of the police officers when they arrive to explain the situation.

Katsuki stops beside Hawks, and the girl’s face lights up at the sight of him. “Deku!” She looks like she just got told she was going to Disneyland. She can’t be any older than three or four, with baby fat still clinging to her cheeks that make her look like a chipmunk. Hawks, horrifyingly, puts the girl in his arms when she makes grabby hands at him.

He tries to ignore it, but has the decency to not drop her. No way Deku would forgive him for that one.

“This little sweet just turned four,” Hawks explains. “I suspect she might have came in contact with you both at the same time a few minutes ago when her quirk manifested.”

“Just as well, ‘cause it ain’t him,” he gestures with his head in the general direction of the man now being apprehended by police as feathers return in a rush to Hawks’ wings. Behind them, firefighters are dealing with the burning building.

The girl gets put in her mandatory quirk training course after that. In special circumstances, when the effects of a quirk manifesting are deadly, training can be fast-tracked or even performed with the people affected present (or more likely reversed by someone with a similar quirk), but this is not one of those circumstances. Since he and Deku are already legally a duo (and engaged), a mere bodyswap doesn’t constitute an emergency. They’re judged to be more than capable of making do with the situation until she gains control of the power, and Katsuki would be pissed if they didn’t immediately find out their quirks also transferred.

And thus, the long process of learning each other’s quirks begins. Well, long for Katsuki, anyway, since damn Deku has such a fucking long list of them. He gets the hang of Blackwhip first, quickly picking up the motions while Deku rambles and rants about visualising tree roots reaching down his forearms to his elbows and warns that it might feel a bit tingly.

He gets the hang of One for All next, teaching Deku the same percentage method he uses himself , and then the more complicated method of controlling how much of his sweat he detonates at once to control the size of the explosions.

They spend the rest of the day teaching Katsuki the intricacies of Float, Smokescreen, Fa Jin, and Gear Shift. Danger sense explains itself when a falling piece of concrete from one of Deku’s explosions propels him into roundhouse kicking it away.

It’s a long, long week off from work learning each other’s quirks (because they aren’t fit to work without a handle on powers like these), and longer still when, from day two, Deku starts hounding him to teach him to fly like he does.

It gets annoying fast, and usually Katsuki would just give in, but flying based purely on something so volatile and directional is no easy feat – it’s something he’s practised and developed for years before even getting into UA, and has worked to perfect ever since. The fact that Deku stumbled when standing up in his body for the first time doesn’t inspire much confidence, and he tells Deku that, in no uncertain words.

But he keeps pushing it.

Every day, as Deku teaches him something new, he follows it up with a request to learn to fly, and it always ends with Katsuki disagreeing and telling him again how dangerous it is and that if Deku breaks his neck while wearing his skin, he’ll bring him back to life to swap their bodies back and kill him himself.

He’s not proud of that one, though Deku seems to take it as a joke in the moment.

He’s grateful for that, so he doesn’t have to apologise.

He does, anyway. He’s gotten better at that over the years.

Adjusting to each other’s bodies is weird. For the first time, he gets to hear and see and smell what he’s like to other people. He smells smoky, something he’d never picked up on himself, but he guesses makes sense, but he also smells like caramel, and he’d thought Deku had been lying when he told him that months ago, but apparently it’s true.

Around day six, Katsuki starts to notice a change in Deku’s demeanour, and not in a good way (and it has nothing to do with adjusting to a different body, they’d already gotten the hang of that) (It’s scary how quickly one can adjust to something as strange as inhabiting another person’s body).

1. Deku becomes avoidant.

It’s not so obvious as when Katsuki enters a room, Deku leaves it, but his tells are something Katsuki is well familiar with. Deku’s avoiding something , because he’s avoiding eye contact. Deku’s avoiding something, because he’s avoiding eating in front of him.

Katsuki begins to wonder if he’s eating at all, and makes sure to tell him that if he malnourishes his body, he’s in big trouble, young man. That pulls a weak laugh from Deku, but he still doesn’t look him in the eye.

Deku’s avoiding something , because there’s a noticeable difference in how often they touch. He chalks it up to Deku being just as weirded out as he is by seeing his own face everywhere and brushes off how Deku flinches when Katsuki touches his hand.

2. Deku becomes quiet.

In the early days of the switch, even in Katsuki’s body, Deku continued his habit of mumbling his thoughts aloud, trying to make sense of the nature of the switch, how it could have been pulled off, trying to analyse the intricacies of Katsuki’s quirk for his own education, teaching Katsuki about his own quirk(s) in far too much detail.

The sudden quiet, even if he’d told Deku to knock it off because hearing his own voice mumble things is fucking creepy , is almost more unsettling.

3. Deku becomes tired.

He knows what exhaustion looks like in his own body. It looks like limbs hanging heavy, heavy rings around the eyes, a pallor to his face that makes him look ill. It doesn’t make sense, because they’d swapped workout regimens and diets as soon as they realised they were going to be stuck like this for a little while. Katsuki’s body should be in top shape. He knows he’s going to bed on time, because they go to bed at the same time when they don’t have a shift, and they’ve only just gotten back to work.

Deku begins to reflect how Katsuki treated himself in high school, when he was pushing himself too hard, too fast, in an attempt to catch up to Deku’s sudden influx of power, and suddenly, it clicks.

Deku is training himself in secret. He should have seen it coming. He knows him, better than anyone, and he should have known the nerd wouldn’t be able to resist learning something about Katsuki’s quirk, even if Katsuki himself won’t teach him.

So, Katsuki swings by their gym one day. It’s not really a gym per se, not the same kind that civilians use. Heroes require much more heavy-duty infrastructure. It’s more of a quirk training ground, with various structures to climb and destroy. He finds Deku in the pit (exactly what it sounds like, a featureless concrete pit with a ladder jutting out from one of the walls) , where Deku ’s directing blasts at the ground in an attempt to move himself straight up , and getting the angle wrong. Katsuki stands at the top, slouched, hands buried in his pockets, as he watches Deku fling himself into the wall over and over again. It’d almost be entertaining, if Deku weren’t going to break his fucking neck doing it.

He checks his surroundings. The gym’s empty.

Katsuki uses Blackwhip to latch onto the top rung of the ladder leading down into the pit and rappels down.

Deku must not have heard him come in, because he shouts and falls on his ass when he turns and sees Katsuki there, to which Katsuki can’t help but snort a little, breaking his frown just slightly.

It settles back in place very quickly.

“So this is why you’ve been so run down,” Katsuki accuses, and he hates that Deku’s voice doesn’t have enough bite, enough grit, to express how angry he is that Deku would go behind his back like this.

Deku looks at him like he’d told him off for something childish, offended and incredulous. He opens his arms as his eyes dart around the room, as if to emphasise what he’s about to say. “Well you didn’t give me much choice,” he points out. “You wouldn’t teach me!”

5. Deku becomes combative.

Now this is hitting too close to home. It’s like he’s staring in a damn mirror, in more ways than just literal.

“Be fair!” Deku continues, pleading. “I taught you every damn thing there is to know about my quirks – in days -” Katsuki hadn’t utilised most of them, to be fair. Once he got the hang of the percentage system for One for All, he had no use for Fa Jin, not if he didn’t want to absolutely ruin Deku’s body. Smokescreen and Float are functionally useless in his day-to-day. Danger sense is passive. Blackwhip is his favourite. “And here I am, stuck with only half a quirk – what was I supposed to do?”

Katsuki’s frown deepens. He watches Deku’s face pinch, sure the words stop doing that with my face are on the tip of his tongue, but Katsuki speaks before he can say it.

“I told you already, nerd, it’s too dangerous for the amount of time we have with each other’s quirks-”

“And what if this happens again?” Katsuki opens his mouth to respond, but Deku keeps going. “What if the girl never gets her quirk under control? What if we’re stuck like this for years ? Or, even if it is only a few weeks, what if a civilian dies during that time, because I have no range of motion?” There’s more he wants to say, he sees it, but words tumble out of Katsuki’s mouth. It’s his damn turn to speak.

“Deku, I studied aerodynamics for years before I even thought to attempt this shit. It’s dangerous! You don’t have years to figure it out. It’s not something I can teach you in days or weeks, it’s all fucking muscle memory. You’re so fucking reckless , I didn’t want you to get my ass killed and have to look in the mirror and see your corpse every day for the rest of my life!”

6. Deku becomes angry.

“Oh, save it, Kacchan-” That gives him pause. Deku never speaks to him this plainly, this riddled with anger. In his own mouth, it sounds natural, but knowing Deku is the one piloting it makes him feel… Unsettled, somehow. “Tell me what you really mean,” he demands, and Katsuki feels his face begin to grow hot – a natural bodily reaction for Deku, he’s found. “Go on. Tell me you think I’m too stupid and weak to pick up your awesome technique.” There are tears in his eyes.

Everything about their bodies is the same, except the eyes. Katsuki thinks he looks weird with green. Deku says he looks weird with red. It feels wrong on a large scale, but when all they can see is each others eyes as they snuggle close in bed, they can almost pretend things are still normal.

There’s nothing normal about the way Deku shouts at him, and Katsuki feels his body tense, steeling for the mounting argument. He doesn’t want this to turn physical, not when Deku is already showing clear signs of quirk overuse.

“Because you are that stupid-” Katsuki says hotly, and fuck , he hadn’t meant to say that. Not like that. “You throw yourself at any problem that comes your way like a damn meat shield. You’ve done it so many times, asshole! Look at yourself!” He gestures with both hands to the body he’s inhabiting, then pulls off his shirt to show Deku all the scars that litter and pucker his skin, from the massive one on his upper arm to the delicate fractures of skin on his hands, two of the oldest mars on his otherwise beautiful skin. “You’ve got the scars to prove it,” Katsuki spits, dropping his shirt to the ground.

Deku doesn’t look. He’s quiet for too long.

2. Deku becomes quiet.

Katsuki’s about to break the silence that has fallen in the space between them, when Deku opens his mouth and asks, pitifully, voice choked with tears (he hates the sound), “Do you love me?”

As if there were any doubt. His face feels hotter, his stomach twisting in knots.

But when he goes to respond, he can’t get the words out. They catch in his throat. Saying it to Deku had become so easy over time, but saying it to his own face is a whole different beast, and Katsuki realizes then that he hasn’t told Deku he loves him since the switch. A flush of shame crashes into him, pulling the air from his lungs. He loves Deku. He does. He wouldn’t be fucking marrying him otherwise.

Deku doesn’t look up. Doesn’t move.

“If I have to wake up every morning and see your face staring back at me in the mirror instead of beside me, what the fuck do you think I’d do?” He watches Deku tense, consider the words, think of a response. He hardly moves. Katsuki holds his breath.

“I know what you wouldn’t do,” Deku finally says, and that grabs Katsuki’s attention.

“Yeah?”

Deku looks up. “Forgive yourself.”

Katsuki’s body (Deku’s body) goes stiff as a board. He freezes, staring back at his own face, unblinking. Because it’s true .

When Katsuki takes too long to respond, standing there and gaping like a fucking fish, Deku continues. “Kacchan, I can only hurt people like this. What kind of hero does that make me?”

Katsuki’s eyes (Deku’s eyes) go wider. The notion of Katsuki’s quirk being primarily and objectively destructive is something he’s heard many times over many years. Even the accusation of it only being that is nothing new to Katsuki, but it still fucking hurts , especially coming from Deku, who’d been in awe of the quirk since its conception.

Katsuki kind of wants to hurt him back.

“You, of all people, should know you can fight and protect without a damn quirk.”

Deku has to take a moment to digest that, and Katsuki almost feels as if he’s won, as if he’s successfully gotten the last word in.

But he could never leave well enough alone, now, could he? He continues. “And by the way, thanks for fucking reminding me.” Deku has the gall to look confused, so Katsuki spells it out for him. “You can only hurt, right? Because of my quirk, right?” The look of horror and understanding is grossly satisfying, even if it’s on his own face. Especially since it’s on your own face, his mind supplies unhelpfully. “Like I haven’t heard it a fucking million times before.” The wince is equally as terribly satisfying.

“Kacchan, you know I didn’t mean it like that,” he says, and Katsuki nearly combusts on the spot with the wave of anger that floods through him.

“Then what the fuck did you mean, Deku?! What could you have possibly meant that doesn’t conveniently line up with every shitty thing I’ve been told about my quirk since day one?!” He misses the reverence in Deku’s eyes. When had that dulled?

Deku looks choked for words for a moment, but he quickly finds them again. “It’s not your quirk!” He exclaims, scrambling to explain, and Katsuki is ready to make this fight physical before he goes to summon the familiar pops in his palm only for a strand of Blackwhip to come out instead. It immediately dissipates when he relaxes his hand, and Deku continues. “It’s me! You found this incredible way to use something that traditionally, is only used for destruction, and you turned it into a tool to help people! You made this power something incredible.” Katsuki stares.

He stares long and hard, waiting for more, waiting for Deku to tell him… What, that it was all a joke? That he actually secretly hates Katsuki and his power and wishes he’d drop dead? He doesn’t know what to make of all the thoughts and emotions zipping around inside him, and more of them get added to the pile as Deku stomps towards him. Katsuki tenses, expecting a slap or something, but then Deku, with his hands, with his mouth, grabs him with both hands around his neck and yanks him down into a kiss.

It’s fucking weird.

They hadn’t really done this since swapping – they’d tried, at first, but it devolved too quickly into giggles for them to build any sort of mood. Katsuki was grateful at the time, and now, because if he can’t even say I love you to his own face, what makes him think he can treat it with any sort of kindness? The kindness that Deku deserves, after the world - after he had been so cruel to him.

Katsuki will spend the rest of his life trying to amend the mistakes of his childhood.

The kiss feels physically wrong. He tastes too smoky. He’s used to kissing Deku’s chapped lips, but now he’s the one with chapped lips, and that’s a whole new sensory thing to deal with. Deku isn’t gentle about the kiss, either. He nips and sucks hard, and Katsuki takes too long to get into it, evidently, because he pulls back soon after, eyes swimming.

Katsuki’s heart pounds. Even after all this time, he still hates making Deku cry.

“I won’t if you don’t want to,” he says, barely a whisper.

Katsuki sucks in a breath. “Let’s go home,” he says, and kisses him again.

They don’t go home right away. After a week without touching (for good reason), they’re suddenly hungry, and he’s actually surprised by how aggressive Deku can be when he’s pent up. He finds himself pinned to the wall of the pit by his hips, a thigh between his legs, and teeth on his neck, and he complains about nothing because it’s the most alive he’s felt in Deku’s body.

Something he hadn’t considered until he’s in the throes of it is that Deku knows exactly where his own body is most sensitive, and he knows exactly where and how to touch it to bring out these embarrassing little noises that Katsuki knows are coming from him, but it’s somewhat less embarrassing since he’s doing it with Deku’s voice. He’s hard against Deku’s thigh in seconds of the treatment, and the nerd has the gall to fucking snicker at him when he notices.

At that, Katsuki huffs and pushes Deku away from him, eyes darkened. “Home,” he says again, in a serious, no-nonsense tone. Deku tries to lean in to give him one more kiss, and Katsuki spins him around and pushes him towards the ladder. “Now,” he adds, leaving no room for argument. Deku laughs, and he doesn’t like how the sound makes his stomach tighten.

Once in the door, they waste no time. They’re on each other before they’ve even kicked off their shoes, with Katsuki pressing Deku up against the wall, hands wandering, touching, feeling. It’s alien but also not. He’s touched himself before, of course, but not like this, not from the second person. Still, he thinks he can do something akin to the neck attention Deku had given himself, as his hand finds Deku’s (his own) hip, sliding down to his thigh, and lifting it to settle on Katsuki’s hip as he grinds into him. It pulls a satisfying gasp from Deku’s mouth, and Katsuki quickly gets lost in the feeling, mimicking motions Deku loves to use on him and also throwing a couple of his own in there – things he wishes Deku would do more often but didn’t care enough to ask for. He grabs his waist, his hips, his thighs, squishing the relaxed muscle. His hand goes flat on Deku’s stomach, sliding upwards underneath the fabric.

Deku has been looking at him the whole time like he’s still waiting for that kiss, so Katsuki caves and gives it to him. The kiss is not as careful as the touching. The kiss is something familiar, something he doesn’t need to feel out and fumble around. Even in each other’s bodies, it’s a dance they know and can do with their eyes closed. That said, it’s damn aggressive. It’s all teeth.

Only once Katsuki tastes blood is he satisfied, then he lets Deku down only to pick him up over his shoulder (damn, is he really that easy to lift?) and haul his ass to the bedroom, throwing him down on the titular piece of furniture with no finesse, only hunger.

It’s extremely weird, to feel this, while looking at that. Knowing Deku is the one behind his own face doesn’t cancel out that he’s looking at his own face, and this is a kind of interaction he never thought he’d have to experience. It’s confronting. It’s weird.

Deku must notice his hesitation, because his expression goes from mildly-annoyed-at-being-tossed-around to mildly concerned, but Katsuki doesn’t give him a chance to ask, because if he asks, he’ll break. He doesn’t want to get into all that shit. He just wants to fuck. Katsuki boxes him in against the surface of the bed and kisses him, hard. Deku follows his example, a tiny noise escaping from him as they let their eyes close and allow themselves to feel as if things are normal. When he goes to grab thick, curly hair and gets a handful of straight and fluffy, though, it startles him into opening his eyes as he pulls away.

Normally, he’d be admiring his work – admiring the way Deku’s lip trickles blood, all swollen and red.

But it’s his own face, and he looks too vulnerable, too real. Katsuki doesn’t even like looking in the mirror on a regular day, so this is… Too much. But he still can’t bring himself to talk about it, so he begins work tugging down Deku’s pants instead. Deku takes the hint and lifts his hips to make the action easier, leaving him in just boxers, which hang low and bunched on his hips, tugged partially by his pants. Deku doesn’t tease him, which he appreciates.

He sits up a little, brings a hand to Katsuki’s cheek, cups his face with care. His expression is still pinched. Doesn’t match the gentleness of the action. Katsuki wonders if this is what it looks like when he tries to be gentle. “You’re thinking,” Deku says, and Katsuki huffs.

“This is weird,” he says. “This is going to be so fucking weird.”

“We can sto-”

“Hell no.”

Deku yips in surprise when Katsuki kisses him again, but he quickly flips them over, straddling Katsuki and pinning him by the wrists with both hands.

“Why is your body’s default mode anger?” He asks, and Katsuki just kind of smirks, because he knows what that feels like. “This sucks,” he continues.

“You still mad about the flyi-”

“Yes I’m still mad about the flying thing,” Deku huffs.

“Well I can answer that question,” Katsuki replies, rolling his hips up to grind against Deku through their clothes. “My body’s always in a damn fight response. Makes adrenaline to combat the nitroclycerin so my BP doesn’t drop to fucking zero.” Deku is trying so hard not to whine at the sensation of Katsuki grinding against him. It only partially succeeds. Katsuki uses the opportunity to slip out of Deku’s grasp.

“That s-sucks,” Deku’s gasps as Katsuki’s newly freed hands find his hips and pull him down harder, increasing the pressure. If Deku thought he was going to get the upper hand by physically being on top, then he’s got another thing comi-

Deku’s hand (his own hand) finds his throat, resting over his hammering pulse without squeezing.

Katsuki’s had nightmares like this, his own body and face looming over him, both hands wrapped tight around his throat until his eyes bug out or he simply stops breathing. He’s woken in a cold sweat and with too many explosions too many fucking times.

“Tap me twice to stop,” Deku says, sensing his unease.

He still waits for Katsuki to nod before he begins to carefully tighten his grip. He hardly touches the windpipe – they know not to fuck with something so delicate. He more digs the pads of his fingers into either side of his throat, right under the jaw. When they were just beginning to feel things out, Katsuki had had to teach him how to choke safely, that it was more about a feeling of lightheadedness rather than not being able to breathe.

“I want to be mean to you,” Deku confesses as he sits above him, squeezing him into more and more shallow breaths. He loosens his grip so Katsuki can respond.

Katsuki looks at Deku, looks at himself, and recognises the anger simmering just under the surface. He’s glad Deku is able to control it, that he hasn’t pushed past their regular limits when it comes to choking. He’s also fucking excited, his skin buzzing with electricity as he thinks about the potential of Deku being mean to him, of pushing those limits, even if just for a second.

He grins, too wide for Deku’s face, too full of mischief. “Then do it,” he says.

Immediately, Katsuki feels like he may have messed up. Deku’s fingers tighten again around his throat as he shifts, sitting on his tensed stomach, reaching behind him to unpick his pants, but doesn’t touch his aching cock just yet. Instead, he brings his hand back to Katsuki’s face, pressing three fingers against his closed lips and says “Go on.”

Katsuki opens his mouth and takes the fingers on his tongue. He’s not careful about it- teeth drag against the digits as Katsuki flicks his tongue between fingers, groaning whenever Deku tightens his grip around his throat.

Deku removes his fingers from Katsuki’s mouth and moves back down to reach into his pants, to get his dick out, to squeeze the base with so much force it’s painful for a moment. When he begins to squirm visibly, Deku releases his grip again. “Fu-” He starts, before being cut off.

“You’re an asshole, you know that?” Deku asks, using his spit-slicked hand to stroke up and down. Spit’s like, the worst lube on earth. Dries too quickly, and it’s not even really that slick to begin with. He’s sure water would be a better lube. His calloused, burned fingers are already tugging on the sensitive skin, and Katsuki continues to squirm as he’s touched. “You’re such an asshole, and I try to be the bigger person and make it up, and for what?” Katsuki’s hand finds the wrist responsible for choking him and squeezes it tightly.

Katsuki’s head is going fuzzy, his mouth feeling thick, but he still manages to speak. “Fuck you.” Creative.

“See, this is what I mean,” Deku continues. "You just shut down everything I say when you don't wanna hear it." His hand continues to move up and down the length of his dick, but there’s not enough pressure.

He’s teasing me, Katsuki realises. Fucking asshole.

Katsuki wants to talk, wants to fight back, wants to curse Deku out for his sterling fucking deduction, but his vision is beginning to swim, black spots appearing at the edges, and he finds himself hoping Deku can discern the signs of needing a break even on his own face. “Pot… Meet kettle,” he wheezes. His voice sounds so raw, and the biting, broken laugh that follows sounds entirely unnatural.

Deku must agree, because he ceases stroking and squeezes the base of his dick again, hard enough to momentarily blind him of all pleasure he’d brought before that, jerking in pain. His hand on his throat still doesn’t loosen. Katsuki doesn’t tap him. Deku leans in close, so close that it’s easy to pretend those eyes are where they’re meant to be, in Deku’s head instead of his own. “I’m not letting you come until you apologise,” he warns.

Katsuki’s not sure if this is fun anymore. It’s like too many nightmares come to life. It’s like the too many times he’s smashed a mirror and cut up his knuckles because all he can see is his Mother’s face as she rips him apart. It’s like too many times he’s beaten himself black and blue while training by going too hard, too fast, doing too much. It’s like the too many times he’s made himself hurt because apparently that’s all he’s good for – making people hurt. Fuck, Deku said it his damn self. It’s like the too many times he’s used the hurt as an ignored cry for help.

Katsuki’s not having fun anymore. He’s angry, too, now, and the fact that his own face is the one looming over him, making his vision nearly black at the edges, is screwing with his head. He wonders if Deku would stop if he passed out.

Probably would, the fucking goody-two-shoes.

But then again, he knows what it’s like to be all keyed up in his own body.

He might not. Wouldn’t that be something?

A shameful burst of arousal shoots through him. He spits in his own face, though he’s pretty sure he misses with his vision swimming the way it is. “Fuck ‘ou,” he says again, for good measure.

Deku spits back at him, and he feels it land on his nose and dribble down his cheek. He doesn’t move to wipe it away, trying to prove he’s unbothered.

“Is that all you know how to say?” Deku asks, and the hand is back on his cock, gone from dried-spit sticky to calloused and rough. It feels like Deku intends to rub him raw, to make him chafe at work.

His fingers are still closed around Katsuki’s throat. He has to be cramping by now, but he holds steady at their pressure limit, as much as Katsuki ever allows him to do. He almost wants Deku to squeeze him more , to go beyond their limit and show him what he can really do.

“Y-you’re n-‘ot b-better than me.” He stutters out in broken gasps.

"Of course I'm not," Deku huffs. "You made damn sure of that, asshole-"

One hand still squeezes Deku’s wrist, but the other moves to where he sits, pressing hard against where he knows his clit is and moving strong fingers up and down. “Buh-bet you’re f-fucking soaked doin’ this-” He’s right. He can feel how wet he is through the boxers. Now isn’t that something?

Deku chokes on a moan, and he’s gotta say, he’s enjoying being the one who can reduce Deku to whimpers this quickly. Well, that’s until Deku pins Katsuki’s hand. His cock still stands proudly, waiting for more stimulation. "Don't touch me," Deku growls. Assisted by Katsuki’s gravelly voice, trying to sound aggressive and mean finally works for Deku.

But before the biting animal came back out, Deku (himself) had looked flustered, vulnerable, shaken, almost broken at the unexpected touch, and Katsuki thinks yes, yes , more of that.

Katsuki activates Blackwhip, six squirming tendrils, quick as striking snakes, shooting out to grab hold of Deku. Two grab his wrists, dragging them up above his head while another wraps around his neck, and another around his knee as he flips them over. Katsuki coughs and sputters, trying not to fucking slump at the sudden rush of being able to breathe properly as he sits on he knees inches away from Deku.

“Fine then.” He rasps, rubbing his throat with a wince. “I won’t. God, you’re annoying.”

One unused tendril wraps around Deku’s other knee to drag his legs apart, while the last one goes to the nightstand. He flashes Deku a vicious grin as he grabs a bullet vibrator from it, brings it to Deku’s spread legs, and presses it to his cunt through his underwear . He clicks it to the highest setting right away, and his grin only widens as he watches Deku begin to squirm. “Y-you’re cheating ,” Deku gasps, voice shaky like he’s trying not to moan , and Katsuki just laughs at him before he puts on an expression of mock pity. He knows Deku can see the anger simmering behind it.

“Am I being unfair ?” He coos with an ugly sneer, the tendril around Deku’s neck (his own neck) slipping away and dissipating, only to be replaced with a scarred hand. Katsuki tightens and tightens, his lip turning up in a snarl. Deku’s breath hitches and his eyes go wide, so he loosens his grip. “ Nothing in life is fair , you piece of shit, you should know that better than anyone.”

He leans over Deku, either arm braced on either side. It almost looks like he’s going to kiss him, or perhaps bite him, but then he shifts his weight and grabs his shirt instead, yanking hard enough for it to tear. And there on his shoulder, revealed by torn-away fabric, sits one of his many sensitive scars, the stab wound Shigaraki had left when Katsuki came to Deku’s defence. Katsuki bites it, and it pulls a satisfying yelp from Deku’s throat. He knows exactly how it feels, and he wants it to hurt. He only releases when he tastes blood again, then sits back up and pulls back the waistband of Deku’s boxers with a finger while the tendril with the vibrator slip into his clothes to press inside him. Good luck squirming away from that, Deku.

There’s a lovely mark left on his shoulder where Katsuki bit him when he pulls back, and though he can tell Deku is trying to be quiet (probably thinking he won’t give him the satisfaction or something), a whimper still escapes his lips, accompanied by a name he’d heard all his life. “K-Kacchan.”

It lights his nerves on fire, and not in a good way. It makes him livid. It makes him scared. He puts his hand on Deku’s throat again. Some hind part of his brain tells him it’s too much, to let up, but he doesn’t listen to it, his fingers tightening too quickly . “Don’t fucking call me that,” he hisses. “ You don’t get to call me that! ” He loosens his grip again, just to make breathing a struggle and not impossible, and glares at his own body before him, struggling for breath. “ Pathetic, ” he spits, voice low, low enough he’s not sure if Deku’s (his own) blast- damaged ears even pick it up.

Deku keeps squirming, writhing around the vibrator like he’s…

Katsuki recognises when Deku comes and becomes oversensitive, and he consider s keeping it going, considers making him come over and over until he passes out, but then his eyes begin to roll back in his head as a thin line of drool drips from the side of his mouth, and he’s only able to kick weakly at Katsuki as a warning, his hands still linked above his head by Blackwhip.

Katsuki stops everything then. Both hands yank away from Deku as if he’s been bitten, Blackwhip retreating. It takes the vibrator with it, and the sound of it pisses him off, so he turns it off, then sits on his feet and watches Deku, watches himself come out of that mess. He watches him take about thirty seconds to catch his breath.

He watches his face scrunch as soon as their eyes meet. He watches Deku cry, raw and shaking and terrible, absolutely horrible. He watches as Deku weakly forces his leg to move and push him away.

He has to swallow down his own nausea as Deku does it, his head swimming with realisations of how he always hurts people , even when he doesn’t mean to.

He hurt Deku.

He hurt Deku.

Deku’s hurt.

It’s all his fault.

He didn’t meant to.

He hurt Deku.

It’s all his fault.

It’s all his fault.

“I…” He starts, and suddenly his mouth and throat feel so dry. Normally, he’d apologise right away. He’d gotten so good at it. But he’s looking at his own face, and since when has he deserved that apology?

Like a fucking coward, he makes himself barely presentable for the public eye and leaves their apartment, leaves Deku in bed by himself, leave s him to sit with an unpack everything that just happened by himself .

What the fuck is wrong with him?

There’s something wrong with him, because he doesn’t go back home. He somehow manages to talk Kirishima into letting him crash on his couch, and he says somehow because he doesn’t fucking lie about what happened. He doesn’t make himself out to be a victim in the situation. He doesn’t shy away from the fact that he has fucked up , because he’s always fucking up and hurting people-

“Hey. No, relax,” Kirishima’s voice is like a beacon in the night, guiding him back to his mind. Kirishima’s touch is a grounding force, steady and familiar, the hand on his shoulder guiding him back to his body (not his body, not his body ). Katsuki has no concept of where he even is until Kirishima tugs him into a hug, and then he’s in his best friend’s arms, head buried in his shoulder as he realizes he’s crying.

“You’re stressed,” Kirishima soothes as best he can. “Take a few days. Camp out here. If you’re not up to work, don’t go in.”

If Deku does, the public will have questions. They’re a duo. They don’t work on different schedules, they work together .

Katsuki realizes then just how much of his life revolves around Deku. They live together, they work together, and they plan on spending the rest of their lives-

Does Deku still want that?

The question makes his blood run cold, a frigid wash of ice down his spine. Somehow, it hadn’t occurred to him until now that he might have fucked up fucked up, that he might have ruined everything for good. He can’t imagine his life without Deku in it. He literally cannot imagine the concept of being without that presence.

Katsuki ends up hearing through Kirishima that Deku had, indeed, gone back to work.

Katsuki’s phone has been silent.

It leaves him feeling empty.

He does nothing, the first day.

The second day, he sends a text.

I’m so sorry, Izuku. Can we talk?

It gets left on read.

Katsuki doesn’t blame him.

The third day, he sends another text.

Please.

It doesn’t even get read.

The third day, Katsuki is pinged by a nearby hero for assistance, his pager flashing and beeping at him like it has the right to remind him that his time off is well and truly up, and that he’s on call. Can’t they have their fucking emergency outside the two-kilometre radius?

It’s probably good for him to have something to actually distract him, though, so he g ears up in record time and goes .

------------------

“Japan mourns the loss tonight of her Number Three Hero, Midoriya Izuku, better known as Deku.” The TV announcer has seaweed in her teeth. “Hit with a quirk last week along with his hero duo Dynamight, the two of them swapped bodies, and this was not resolved before Deku’s untimely passing .” The hospital waiting room is fucking frigid. “In a way, it’s like he’s still around.”

“Fuck this,” Katsuki whispers to himself. He gets up and leaves, and none of the hospital staff stop him as he walks out the building to find a quiet spot (around the corner from the smoker’s area), and make a phone call.

The air outside is mildly more temperate than the hospital waiting room, but he still bounces his leg as his phone dials.

When the receiver clicks, Katsuki doesn’t wait for the other person to speak first.

“How’s Naomi doing with her quirk training?”

“Dek- Dynamight, right?”

“Mm. How’s she coming along?”

He needs to get out of his hero costume. It’s all sweaty and bloody. (Deku’s blood. His own blood).

“Well she’s made remarkable progress. I…” His voice lowers, like he’s cupping a hand over the receiver. “I’m sorry we were too late.”

“It’s not,” Katsuki says easily, because he’s made up his mind.

There’s silence on the other end for a moment. Katsuki lets it hang.

“I-I beg your pardon?”

“I said,” he drawls, strangely calm, Deku’s voice objectively soothing and subjectively nightmare fuel in the still air. “It’s not too late. Get her to xxxxx hospital and swap us.”

There’s another stretch of silence. Katsuki lets it hang. There’s a bit of shuffling on the other end.

“W-we don’t know how the quirk would react if one of the participants are deceased,” he begins to explain, and Katsuki does not care . “If it does anything at all, we don’t know if it would mean both of you cease or…” Ah, now he’s getting it. “Y-you give your life for his.”

“Bingo,” Katsuki says, and tries not to laugh.

It’s the absurdity of the whole situation, how the exact thing Katsuki said would happen, did happen, and now he’s all alone stuck wearing the face of the person he loved most, as if he were the one who deserved to live .

Katsuki knows, rationally, the deeper implications of risking One for All’s legacy, but he thinks the world can go on without a miracle quirk.

He thinks he can’t without his miracle.