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Katsuki always thought Izuku was creepy. Even when they were little, the boy had eyes that were always too wide, and too empty. His smiles felt like the grin of a predator- threatening and wholly unnerving. He couldn’t really ditch the kid, though, since his parents were friends with his mom, and he’d get grounded for the rest of his life if his mom thought he was being mean to him. So he let Izuku tag along behind him, figuring he’d look past the creepiness since he was such a good ego boost for him, always complimenting him with that oddly lilting voice of his. He couldn’t tell if the other kids at school just didn’t notice how creepy Izuku was, or if they didn’t care.
Katsuki couldn’t give a rat's ass about whether someone had a quirk or not, it didn’t matter to him who was weak or strong, since he was going to be stronger than all of them anyway. But when Izuku came to school one day when they were six, uncharacteristically meek, and told them he’d likely never develop a quirk, Katsuki saw his chance and grabbed it. He claimed that Izuku could no longer hang around him, since he had no quirk and was therefore too weak to be his friend.
He’d deny it til his deathbed, but the look Izuku gave him when he announced the end of their friendship scared him so badly, he couldn’t sleep that night. He held firm in his resolve though, and while he always kept an eye trained on him at school, he eventually loosened up and enjoyed sitting at the top of the food chain at their elementary and then after a few years, their middle school. Izuku never tried to talk to him again after he cast him aside, which had worried him at first, but he stopped questioning and took it as the blessing it was.
He pretended like he didn’t see the bruises and poorly-hidden cuts that he started to come to school with. Eventually, they just became a normal thing to see Izuku with, so he didn’t even notice when they would get worse, or when he came in with a cast on a broken arm one day.
That’s what he convinced himself, he didn’t notice.
He didn’t notice. He didn’t notice. He didn’t notice.
By their second year in middle school, Katsuki had largely stopped thinking about Izuku. Most people in school ignored him, or maybe he really just faded into the background that well. Which is why he was so caught unaware when Izuku flagged him down after school one day as he was walking home, his face no longer the empty mask it had been for the last couple years, instead he was wearing a deceptively sweet smile that made Katsuki’s blood run a little bit colder.
Katsuki could never really figure out what it was about Izuku that made him so uncomfortable- he had never been anything but kind and quiet. He was just… unnerving. He felt fake to Katsuki, like a mannequin or a marionette doll. He made a good show of it, with his cute little smiles and kiss-ass attitude with adults. Even the kids at school more or less liked him; he just faded into the background so much that he was just never really included with anyone. And Izuku just… didn’t seem to care about that.
“ Kaaacchan~~! Guess what!” Katsuki froze in place, and slowly turned to face Izuku, who had come up behind him on the sidewalk, silent as a shadow. He watched him, wary, as the short boy’s smile grew wide, too wide. It looked like if it stretched any further, it would tear the corners of his mouth. He looked giddy, and covered his mouth with his hands, like he was hiding something.
“What is it, Iz-Deku? Why are you talking to me?” The half-hearted insulting nickname didn’t even register to Izuku, who was now bouncing up and down on his heels. His heart sped up, and he could feel his palms sweating, though it didn’t reassure him like it usually did, having his quirk loaded and ready; if anything, he felt bare and unguarded. Which was fucking stupid , since Izuku was Deku . He was useless, and powerless, and beneath Katsuki. He had no reason to be afraid of the little twerp. He WASN’T AFRAID of Midoriya Izuku.
“Guess, Kacchan~!” With each word, smoke billowed up behind his hands.
Smoke. Smoke? Why was there smoke? What was he playing at, right now?
Oh. His heart felt like it skipped a beat, as the realization dawned on him. It took him a minute to think of it, since Izuku's father had been out of the picture for so long, but his dad had a fire breathing quirk . And- and Izuku- he had smoke coming from his mouth .
Katsuki couldn’t really put a finger on why he was so desperate to convince himself Izuku was just pranking him, and hadn’t developed a quirk. He couldn’t even blame it on not wanting to feel inferior to Izuku strength-wise, as the thought hadn’t even occurred to him, not to mention the years of practice he had on him.
“Oh, I can't just stand here and wait around for you to guess! Look !” With a dramatic flourish, he swept his arms away from his face, an arc of white-tinged-blue fire following the motion. Katsuki hurriedly took a step back, the fire too hot to stand even being near . The fire didn’t dissipate, instead sitting in two roiling balls in Izuku’s palms. Katsuki was battling to keep his quirk in control, the heat not only increasing the sweat produced from his hands, but because of how intensely hot it was, it kept threatening to set off his own quirk.
To his relief, the fire quickly died out in Izuku’s hands, though his eerily-wide smile remained the same.
“Isn’t this great, Kacchan? We can be friends again! Oh, I’m so happy, you have no idea. I missed being by your side every day. Ooh! Oh wow just think about it, we’d be such a fantastic hero duo, dontcha think? It seems I can control fire and you make explosions! ”
Katsuki could think of hundreds of different questions he wanted to ask. He desperately wanted to tell Izuku to fuck off , to fuck off with his creepy bullshit, to leave him alone because he did not want to be in a duo with him, much less be friends again. He had a deep, guttural feeling, though, that he should absolutely not do that.
Izuku’s enthusiasm didn’t die down a bit, even with Katsuki’s long silence. He wanted to choose his words very carefully.
“I thought the doctor said you would never develop a quirk?” He sighed in relief when it seemed that wasn’t the wrong thing to say. He found himself having trouble breathing, though, once he heard what Izuku said next.
“Oh he said it was highly improbable. I did some research on my own, though! I promised you that we’d make it to the top together, and that I wouldn’t hold you back. I learned about something called forced quirks- when a really stressful or dangerous situation causes a quirk to manifest that might otherwise not have.” Katsuki stared at him in disbelief- there was literally no way that Izuku was trying to tell him that he forced his own quirk . He’d seen some stories on the news while his parents were watching, and it was never a pretty story.
“What… what are you trying to say? How could you force manifest a quirk yourself ? How is that even possible?!” Katsuki forced himself to not flinch backwards when Izuku stepped closer to him, much closer than socially acceptable.
“Well I mean, it was kind of a no-brainer. Every instance of forced manifestation seems to happen in some sort of villain situation, right? Whether it be violence at home or by criminals in the street, that’s the common thread. So I just kept going out and finding villains myself! It had an added benefit of giving me some hands-on experience for when I do become a hero, but really I was just interested in getting my quirk.”
Katsuki felt sick. He couldn’t suppress his flinch when Izuku suddenly surged forward and grabbed hold of his hands, spinning him around. Izuku’s hands still felt hot.
“Oh Kacchan~, this is fantastic, isn’t it! All my hard work finally paid off! We should all have dinner together, to celebrate! We haven’t had you and your parents over for dinner in years! Oh, Mom will be so happy. Let’s go see her! I told her the good news yesterday, when it happened, so I’m sure she’ll be more than happy to make some dinner and have everyone over.”
Katsuki couldn’t find it in him to say a single word, letting himself be dragged along behind Izuku. He just… he couldn’t fathom what was going on in Izuku's mind. He seemingly put himself in numerous villain’s paths to try and force a quirk? He purposefully caused himself extreme harm and he just… waltzes back up to Katsuki like nothing is wrong and thinks things will go back to normal?
He’d always known there was something off-putting about him, but now he knew that the boy was fucking insane . And he really couldn’t do anything about it at all, could he? Katsuki could only desperately hope that they didn’t end up going to the same high school, or that he found someone else equally fucked up to transfer his obsession onto.
Dinner with his parents, Inko, and Izuku was incredibly stiff. For Katsuki, anyway. Inko seemed completely unbothered by anything, and didn’t seem to question even a little bit about her son’s sudden quirk manifestation, nor did she seem concerned with his creepy demeanor. His parents were just as oblivious, complimenting him and telling him how glad they were to see that he and Katsuki were getting along again. Katsuki stayed quiet, too shaken to be anything but silent and polite.
The rest of their middle school days that followed were filled with anxiety, Katsuki always feeling like he was being watched, and feeling on edge, as if any wrong thing he said would be the one thing that finally made Izuku snap and get angry.
Katsuki couldn’t put a reason to why he thought Izuku would snap, and drop the goody-two-shoes, all-smiles act, or why he even thought it was an act to begin with, but he decided to err on the side of caution either way.
Katsuki and Izuku trained together fairly often. Katsuki watching as Izuku strengthened in leaps in bounds not only in plain physical power, but in control over his quirk as well. The entrance exams for hero schools were coming up, and Katsuki felt for the first time hope swell in his chest when Izuku said he was applying to any schools nearby just in case, and not just UA. That meant there was a chance for Katsuki to escape him.
They unfortunately had to take the UA test on the same day, but lucky for him only had to take the written portions in the same area, being split up into different groups. Izuku excitedly told him good luck, before running off to find his location. His excitement had been at an all time high for the last few days, never wavering.
Katsuki found the practical exam laughably easy, as he blasted robots apart left and right, letting built up frustration, anger , and fear lead his movements. He headed home immediately, pleased to find that he didn't run into Izuku along the way. Katsuki praised every god that he could think of when he didn’t run into Izuku a single time in the weeks leading up to the first day of school, riding on a high of placing so high in the test and making it into UA, though he really didn’t have any doubts that he could do it.
Walking through the massive gate of UA was exhilarating, and he proudly walked through the halls to his class, 1-A with a rare grin spreading across his face. He was early, like he’d intended, and he snagged his seat from the seating chart so he could watch and size up everyone who arrived. He wasn’t the first one in there, there was a tall, goofy looking guy who was digging through his backpack and pulling out notebooks and an absurd number of colored pens.
He settled into his seat more comfortably, putting his feet up and leaning back with his hands in his pockets. That seemed to get the tall dumbass’s attention, as he marched over with stiff limbs, fixing his stupid square glasses.
“Excuse me! My name is Iida Tenya, and I must ask you to have some respect for your classroom and remove your feet from this desk! It’s disrespectful to not only the classroom, your peers, but your-”
“Oh get bent, Four Eyes. The feet are staying.” The kid sputtered, caught off guard, and he made a chopping motion with his arm that had Katsuki barely keeping in a laugh.
“Heeey man, that’s so not manly to talk to someone like that, we don’t even know each other yet!” A group of a few more kids came walking in, namely the redhead with stupid hair that had spoke up.
“And? Do I look like I’m here to make friends and get to know people? No! I’m here to become the best, so fuck off, Shitty Hair.” The boy reacted similarly to Hand chop guy, mumbling something about being unmanly. More students filed in, being loud and chattering. A few came up to Katsuki and tried to introduce themselves, but they were all similarly turned away. He was in the midst of a particularly fun argument with some pink-haired chick when a very familiar voice cut through the crowd.
“Oh wow! Hi Kacchan! How cool is it that we’re in the same class again?!” Most of the eyes in the class turned to the small, cheerful sunshine-y boy who entered the room, and looked around out of curiosity, trying to figure out who he was talking about. One by one, the eyes followed Izuku’s line of sight to Katsuki, and several people outright cackled, presumably at the nickname.
“ Kacchan?” He heard some people whispering, sniggering.
“... Hi, Izuku. I didn’t think you were in my class.” Izuku bounded up, grinning his familiar fake smile.
“Oh perfect!! Kacchan, look! My seat is just behind yours!” Katsuki felt cold dread seep into his bones. “Kacchan, get your feet off the desk. Class is starting soon, you know?” He said it in a semi-scolding tone, but he heard the underlying tone to it. He decided he didn’t want to test Izuku’s seemingly never-ending patience, and he moved them.
“Oooh~~ looks like Kacchan has a handler, eh?” The girl he dubbed Raccoon Eyes sang, and Katsuki felt anger rise in him. It was familiar.
“SHUT THE FUCK UP.” Everyone around them laughed, though their teacher came slouching in before he could retaliate.
Katsuki despised that he only got fifth in the class during the quirk apprehension test, and he despised even more than Izuku beat him and got fourth. He wanted to rage, and he nearly did, until he saw that Izuku looked legitimately happy . And not his fake kind, either, it looked like there was real emotion on his face. Katsuki didn’t know if it just made him feel relieved, or what it was about it that made his anger cool down.
He decided he’d think about that another time.
He wouldn’t admit it, but he had actually been rather excited for the USJ trip. That was until, of course, they were attacked by villains. He watched, terrified, as one by one his shitty classmates were sucked into portals and dispatched across the facility. He was grabbed too, and the disorienting feeling of the portal just about made him lose his breakfast.
Katsuki found himself unceremoniously dumped in what looked like a ruins zone, and he immediately looked around to take note of his surroundings. He heard what sounded like a fight, and a couple unconscious villains in a somewhat morbid path leading behind a collapsed building.
It was at that moment that Katsuki discovered why he had been so unsettled by Izuku, why he had been scared of him since childhood, why he had always seemed so wrong.
Sat on top of and pinning down a villain, was Midoriya Izuku, crowned in flames and smoke. Katsuki’s eyes looked down Izuku, from his face and fire, following his arms only in time to see him plunge a blade deep into the villain's chest, who sputtered and coughed blood for a moment before going limp. Izuku didn’t stop there, though, as he shoved the knife into the body again and again, a sick squelching sound accompanying it every time.
Katsuki looked around, disbelieving, and realized that every villain’s body he had passed, and more that he was only now seeing, weren’t downed and unconscious, but dead, lying in pools of their own blood that slowly seeped outwards, varying levels of scorch marks decorating them.
This time, Katsuki really did lose his breakfast, as he violently hurled. He kneeled there and retched long after his stomach was empty, and only stopped when a hand suddenly rubbed his back. He startled and jumped away, looking up into the blood-spattered face of Midoriya, who looked unbothered and unperturbed.
“You don’t have to worry, Kacchan. I took care of all the villains here. I’ll just clean up the bodies and then we can go help the rest of the class and Aizawa, alright?” Katsuki couldn’t even nod, his hands shaking violently. He wasn’t sure he could stand. He couldn’t pry his eyes away as Izuku spat impossibly hot flames, engulfing each body until they burnt to ashes that blew away with the wind.
The police report of the USJ didn’t include any villain deaths. No teacher or police questioned him or Izuku, and the weight of that grew heavier on Katsuki with every passing day. Izuku seemed fine; in fact, he seemed better than fine. Everyone in class took to him instantly. Katsuki wanted to scream , to tell them that they needed to stay far, far away from Midoriya Izuku, but he was scared. He would be the first to admit that he was scared, and justifiably so. Every time he started to think he could muster up the courage to tell someone, he’d catch Izuku’s eyes and he’d be reminded of what he saw.
As long as Izuku never hurt anyone good, it was fine to keep quiet, right?
It was pure chance that Katsuki was in Hosu. His internship hadn’t typically involved patrols, and especially not so far out here at night, but he didn’t argue when Best Jeanist dragged him out here.
It was probably also pure chance that he even noticed the notification on his phone in the midst of all the chaos, fire, and Nomus. He saw that it was a location from Izuku, though it had been sent to the whole class’s group chat. He kind of thought he had muted that one already. Briefly, he considered ignoring it, but in the end curiosity and an unplaceable compulsion urged him to make his way to the location.
He got there in time to see the Hero Killer, Stain, raising a blood-speckled katana over Four Eyes’ body, preparing to end him. He didn’t particularly care for the guy, but he also had no desire to see him dead. He blasted his way over to him, knocking him off balance, but he wasn't quick enough to actually land a hit. Stain leapt a ways away, thankfully putting the boy out of danger for the moment.
Izuku was laying on the ground, unmoving, but seemed like he was on the verge of getting up again. He had heard speculations about Stain’s quirk, and it seemed that the paralyzation theory was in the lead.
“Another false hero?! Here to stop me? You’ll have to try much harder than these fake heroes here did- they let pride and petty revenge consume them and their actions. Get in my way, boy, and I’ll have no choice but to kill you as well. I don’t like killing kids, but stand in my way and I’ll easily make the exception.” Katsuki didn’t like letting the bastard ramble on about his bullshit ideals, but he saw Izuku silently rising behind him and he was too smart to let an opportunity go to waste.
He didn’t know what he was going to do, but he was hoping it was something that would catch the lightning-quick villain off guard enough for Katsuki to land a solid blow on him.
“I never let such petty things consume me. I consume them .” Katsuki’s eyes widened in shock as he watched, almost in slow motion, as Stain’s head snapped around in surprise, only for him to be trapped in a headlock by Izuku, and could only watch in horror as he slowly but deftly dragged one of Stain’s own blades across the murderer’s throat.
The gurgle that came from his throat nearly made Katsuki throw up again in a horrifying parallel to the first time he had witnessed Midoriya kill, and could only helplessly watch as Izuku suddenly released his grip, and the man fell limp at his feet. Izuku remained calm, a small smile on his face that Katsuki could only assume had been there the whole time.
Movement behind them alerted Katsuki to the presence of an actual hero, Native, who seemed to be coming out of the effects of Stain’s quirk.
That’s it! Both a licensed hero and one of their classmates saw Izuku murder a man .
Katsuki frantically looked between Iida and Native, desperately searching for even a hint of the fear or disgust that he himself was feeling. He wasn’t seeing it . Why couldn’t he see it? They had to know now, right? They had to see Izuku for how he really was, they had to see past his façade!
They saw… right?
Right?