A/N: Fair warning. This chapter contains probably the worst thing Saiki has done in this entire story. If you really, really aren't okay with dubcon, this would be a point for you to bow out. One relationship in particular will be defined by what is basically hate-sex. And that element doesn't really go away even if both parties end up on board with it.

-(-)-

Best part of battle training? It was the first time the students got to wear their own hero costumes. The entire class had been giddy at the idea and All Might letting them do a badass hero walk out to the training arenas was just icing on the cake! It was quite the ego boost for everyone involved. Even for those with fairly simple costumes, being part of a crowd as eye-catching as they were made them feel like heroes.

Saiki was no exception. He hadn't gone with anything too extravagant in his costume design, He didn't really know what might benefit him most at the outset and the requisition form suggested sticking with things that would benefit quirks directly. He didn't know what that would be either, so he stuck with the basics. It had to be flexible, it had to be durable, and preferably lightweight. The design company had come through on all fronts, having a standard material they use for brawler-style heroes who like to get up close and personal. It was apparently a mass-producible version of what All Might wore, though All Might's hero costumes were produced by Shield Industries using proprietary technology.

Saiki's suit fit a lot of the classic hero aesthetics. Full body skin-tight suit in royal blue with metallic grey boots, gloves and belt for decoration. Running up the arms and legs were a pattern of green up-arrows, as well as one large arrow stamped on the chest. The suit ran right up and over his neck, leaving only his head uncovered.

"Hero team... WIIIIIIIIIIIINS!"

Saiki frowned as he watched the results of the first match through the viewscreens of the control room. The match was... dramatic, that he knew for certain. Izuku Midoriya was heavily injured once again while her team was declared victorious. Meanwhile, Katsumi Bakugo stood completely uninjured and utterly flabbergasted at her defeat.

And the reason for the result was the other half of the battle that barely anyone was paying attention to.

"Unreal..." one of the students muttered as they waited for All Might to return and declare the next match. Finally, the herculean hero returned with three quarters of the match participants, Izuku once again being carted off to Recovery Girl.

The post-match debriefing was mostly spent praising Iida while denigrating those in the furious battle for ignoring the real objective, and Uraraka for not treating the scenario seriously.

Saiki kept an eye on Katsumi as the next battle progressed. Though she tried to hide it, she was as awed as everyone else when the match took only a minute, Shoto Todoroki freezing the villain team, the objective and the entire building in seconds. He would take more amusement at the beating the arrogant girl's pride was taking but he felt the blow to his own pride at the same time. All the work he had done to improve himself, how was he supposed to stand up to that?

Well, increase his cold resistance some more would be a start. He sighed as he realised he would need to start taking ice baths again.

"Villain team C!" All Might announced as part of the next match. Saiki's team, alongside the rich girl in the wonderfully scandalous hero costume. "And they'll be facing... Hero Team G!"

"YES!" the boy with electric yellow hair cheered, his teammate the girl with headphone jacks on her ears settling for a pleased smirk. "You're going down, top scorers! It's gekokujo time, baby!"

"Gekokujo? So we're the villains in power?" Saiki asks, clasping his hands behind his back. "Then I suppose as the overlord it is down to me and my dark mistress of evil to crush you foolish heroes beneath our heels!"

"Hoho! I'm glad to see my students getting into the spirit of the exercise!" All Might bellowed. "Heroes, villains! Follow me to the hideout!"

The world's greatest hero had the hero team wait outside the plain-looking office building while he led the villain team directly to their objective, once again a fairly stereotypical bomb prop. In the moment he left he informed them their prep time had already begun.

Yaoyorozu didn't bother taking the time to explain her quirk, already getting started on pulling fortifications for the bomb room out of herself. "I couldn't quite figure it out, what does your quirk do, Saisei?"

"Call me Saiki," he said, hands in his pockets as he watched Momo work. "It'll be hard to explain the mechanics in the time we have. Basically, I can make myself better at things over time. So I have super strength, speed, agility, endurance, I'm pretty resistant to just about everything."

"That's quite the list!" she admitted, looking impressed. She didn't seem to even notice how she was distracting him by reaching into her cleavage to pull out materials. "It would be best then, to have you out patrolling for them I believe."

"Probably," he shrugged.

Momo pulled out the last strut for blocking the doorway, only to sag with a sigh. "I feel like we're doing this wrong."

"Really?" Saiki asked, not seeing the problem. "I go beat up the heroes, and if I can't, you stop them from getting in here. Seems fine to me."

"Well yes, that's all fine! But I feel like we need to get into the role more! You know, get into character like you did before, like Iida did!" She cleared her throat and struck a pose, thrusting out her chest proudly, raising a hand to her mouth. "Ohohoho!" she suddenly laughed in a painfully fake manner, "With my fortifications, those foolish heroes shall never breach our... Uhh... Our sacred detonation bunker!"

"... Our what?"

"Come on, Saiki!" she pleaded, "Play along!"

He really didn't want to play along with that. "Uhh, yeah, let's do evil I guess."

"You can do better than that! Come on, like before!"

… Well, if she wants him to be a villain... His chin rose so he could look down his nose at her. "Yes, my dark mistress," he purred, hands clasped behind his back once again as he approached his partner in villainy, "Once I have put down those foolish heroes once and for all, we shall rule for eternity together!"

His arms came around her waist, Momo letting out an "Oh!" of surprise as he dipped her, their lips barely an inch away from touching.

"When I return, I want you ready and waiting for me," his hand slipped down over a hip to her belt, "wearing only this." Suddenly, he smiled with a cruel edge to it. "Perhaps I'll even bring the girl back with me for us to play with together? Would you like that?"

Momo, flushed so red she was surprised her face hadn't caught fire, could only respond with a strangled, "Ah?"

Raising her back up and twirling her away as if in a dance, he released her hand and strode through the open door. It took a moment before he started hearing the clang of Momo building a barricade behind him.

"Young Saisei, you know I heard all of that, right?" All Might's voice crackled in his ear. "And everyone saw it?"

"So? Just part of the exercise," Saiki responded but wasn't able to hide his smirk.

The blue-haired boy took a quick survey of the building layout since he still had a little time. It was a lot more cramped than it would seem according to the floor-plan. The biggest problem would be catching the heroes before they could reach Yaoyorozu. Every floor had two stairways up except the first floor to the second and the fourth floor to the fifth. But it was already proven the first floor could be skipped entirely and the objective was on the fourth floor so that was no help to him. However... There was a clear line of sight on the third floor between the two staircases. All he had to do was keep himself concealed on that path and catch them on their way up!

About ten minutes later, Jirou and Kaminari ascended to the third floor, cautiously peeking around a corner, the electric quirk user pulled back, giving his partner a thumbs up as they scurried back down to the second floor.

"So he's watching the stairs," Jirou correctly surmised, "and we know Yaoyorozu is on the floor above."

"Should we split up? He can't chase both of us!" Kaminari suggested.

"You saw him in the quirk tests, I think he can. Not to mention whatever his 'dark mistress' did to secure the bomb room."

"So what? We can't take him on!"

"Sure we can!" Jirou countered, "You said you're like a human stun-gun, that you fried the robots in the entrance exam! All you have to do is touch him!"

"... You think?" Denki asked, starting to like the idea of felling one of the class' titans so early in the school year.

"Gekokujo, right?" Jirou asked with a dry smile.

The electric quirk user swallowed, but nodded firmly. "Right!"

-(-)-

"Oh?" Saiki said aloud as he dropped from his hiding place on the ceiling of clinging to a light fixture. The reason? Denki Kaminari was ignoring the stairs entirely and walking in his direction. "You're approaching me? Instead of running away you're coming right to me?"

Denki had to hold in a laugh. Certainly playing up the villain routine. And quoting one of the greats, even! "I can't beat the shit out of you without coming closer." Not strictly true but he couldn't help continuing the bit.

"Then by all means, get as close as you like!" Saiki offered, opening his arms wide in a welcoming gesture before settling in a rough fighting stance.

Kaminari stepped forward. Again. Again.

Saiki's smile turned eager.

"Heartbeat–"

Kaminari dove into another passage and out of sight!

"–Stereo!"

"W–Gyahhhhh!" Before Saiki could even question, his world was consumed with absurd, deafening noise! He clutched at his head to cover his ears hoping to escape the pain but it was no use!

"Now, Kaminari!"

"GEKOKUJOOOOOOO!" came Kaminari's battle cry as he dove on the unknowing, unhearing Saiki and lit him up like a christmas tree, dumping electricity into his unresisting body!

"Ghhh!" Saiki grunted, pushing through the pain to slam Denki in the chest with both arms, shoving him away with enough force to make the electric boy feel like he was coughing up a lung! "Ghhh!" he groaned out as he forced. His feet. To turn. Around.

And face Jirou. "Ohhh, crap," the punk girl uttered on seeing her opponent will himself towards her. She had run out of options. If she ran, he would chase her down. If she stayed, he would reach her. The best she could do was hope Kaminari could tag him again before he got to her, not knowing Kaminari couldn't even stand, let alone help her. She cringed as Saiki got close to arm's reach away from her and she took a step back towards the stairs.

Not even the slightest bit willing to allow that, Saiki lunged for her and used his superior strength to turn her around, giving him a respite from the wave of sound coming from the speakers in her costume. As he felt the relief of the sound giving out, he collapsed atop her, fumbling for the capture tape and wrapping it around her arms. "Thank you," he told her, strain audible in his voice. "Sound. Never thought of that one so I'm not resistant to it. I'd love to train with you sometime, fix that weakness." With that said, he got up from on top of her, stumbling his way back to Kaminari and doing the same to him too, shrugging off the electric attack the boy attempted as a last stand.

"Villain team WIIIIIN! No, young Yaoyorozu! Costume stays on! The exercise is over!"

-(-)-

"So, MVP of this match, any guesses?"

Momo had been the one to answer in the previous matches but she was both a participant and unaware of the events outside the bomb room. So instead, Kirishima took a stab. "Saisei did a pretty good job taking on both heroes at once!"

"Yes, he defeated both of them. However, his overconfidence in allowing them to attack him as they pleased caused him quite a bit of pain that could have been avoided!"

Saiki was stunned. But he still won, though!

"On top of that, his chosen strategy might have worked out, but it still allowed the enemy more options to deal with him! Stopping on the third floor when there were two routes past him means the hero team could have split up, one of them distracting him while the other attacks their sanctum! There was nothing to stop him from obstructing or destroying one of the staircases in the time it took the hero team to arrive. Instead he waited, and handed the hero team the initiative."

But he stopped them anyway! And even if he hadn't, Momo had it covered!

"No, I believe the MVP of this match has to be Young Jirou!"

"Yeah!" Kaminari cheers, "Gekoku–"

"We can stop saying that now," Jirou interrupted, cutting him down.

"Acting as the tactician of their team, she correctly pinpointed the enemies' locations, scouted them out for confirmation and came up with a suitable plan for dealing with the enemy they were presented with. Had Kaminari considered the capture tape in his ambush, it very well might have worked! Credit must also be given to Young Yaoyorozu for her diligent fortifications but unfortunately she didn't participate in the match enough to be considered MVP."

"Shoot! And we did so well in getting into character too!" Momo complained, apparently still in character as she had her arm wrapped around Saiki's waist as she was pressed into his side.

Not that it comforted Saiki any.

… Well maybe a little.

"Let's draw our next match participants!"

-(-)-

"Hey Creeper."

Saiki's lips pursed as he heard someone get called a creeper as he was walking out of school. That was rude. Glancing behind him to see who it was and who they were talking about, he found Katsumi Bakugo glaring at him. "You're talking to me?"

"Fight me."

"... Excuse me?"

"I said fight me you creepy bastard!" she growled as she took two stomping steps forward.

Well. Her pride had taken a beating today if she was that desperate to prove herself. While his common sense told him he should decline... Saiki's pride hadn't exactly gotten off scot-free either. Discovering a weakness he never considered, single-handedly winning the match and getting no credit for it. He could use a reason to feel like he's on top again too. And as that phrase ran through his mind, he knew exactly how to do it. "Alright."

"You're damn right! Now come at me!"

"No," he denied quickly, "Not here. Right outside of school? Do you want to be suspended? Let's find somewhere private. Out of the way."

Teeth grinding, barely containing her anger, she followed him to the best place he could think of that they wouldn't be bothered. There was a pretty significant bit of woodland area outside of UA. Not really used for anything to his knowledge, maybe survival exercises or something? In any case, it wasn't in use at that moment and that was the important part. "Okay then."

"Finally!" she grinned menacingly, explosions bursting in her upturned hands.

"Ah-ah-ah!" he wagged his finger as his other hand unfastened his tie, blazer and shirt. He couldn't afford to replace them just for something like this. "What are the stakes?"

"What the hell are you talking about, stakes?! It's a fight to see who's better!"

"In that case I wasted your time bringing you out here," he shrugged, both to express his disinterest and take off his shirt. "One demand. Winner gets to demand one thing from the loser."

"Whatever, I don't care about that crap, just fight me!" she yelled, throwing her hands back to blast herself toward him!

As she neared him with literal explosive force, he quickstepped to the side to avoid her charge, not making any move to counter. "Shall I take that as a yes?"

"Fine! Just–!" she swung around and launched a hand towards his face–

He grabbed her by the wrist. "Wonderful." His smile was the one she named him for, that smile he showed in the battle trial, the one that said he just got exactly what he wanted.

Katsumi didn't intend to let him relish in it, her other hand coming from beneath to blast him in the solar plexus. And she did.

And he let her.

It stung, it burned, and it felt like someone punched him in the stomach. Like someone strong punched him in the stomach. He braced to not let the pain show on his face, or his self-flagellation over letting someone hit him assuming he can take it again.

"That stings," is all he said, concealing the other effects as he still held her wrist.

"What the hell–!"

"Heat, blunt force. The usual causes of injury from explosions."

Another explosion from her right hand went off right in front of his face!

… To no visible effect. "And light. Thank you. Forgot about that one. My quirk allowed me to develop a resistance to all of them." With superhuman strength, he put his other arm to her abdomen and flipped her over, slamming her into the dirt! "I'll have to thank Izuku for that one."

"Don't–!" she interrupted herself with a cough as she got to her feet, "Don't you bring up that damn nerd right now! You're fighting me! Take this seriously!"

Saiki weaved to dodge her furious barrage of blasts, all aimed at what should have been debilitating weak points that he had deliberately trained out of himself. "Take you seriously. I've known you all of two days and all I've seen you do is scream, talk shit, and get put down for your own arrogance and temper." As a swing went wide, he took the opportunity to drive a knee into her abdomen. "Take you seriously. I'll take you seriously when you take you seriousl–" Saiki's mouth was suddenly slammed shut by an explosive uppercut.

With enough sweat built up, Bakugou had used an explosion at her elbow to drive her fist forward. "About time you shut up!" she grinned fiercely at finally doing some noticeable damage, only to get picked up by her shoulder and crotch and tossed at a tree.

"Ah," Saiki grunted as he worked his jaw, trying to settle the ache in it. "And I bit my tongue too!" Turning around, he regarded the fallen girl struggling to get her hands under her. "Huh. Your left hand is shaking."

"Fuck you!"

"You're not immune to your own explosions are you?"

"Fuck off and die!"

"No wait," he corrected himself with sudden realisation, "Your right hand is dominant. But that punch was with your left... That's why you don't use that move more often isn't it? Why you didn't use it until you got desperate. You take the full force of the punch in your forearm from both directions."

"Shut up shut up SHUT UP!"

His brow furrowed at her continued attempts to fight. She was standing but one hand clearly wasn't in it anymore. He was actually becoming a little concerned. It was no fun if she destroyed herself. He decidee to make one more attempt to talk her down but after that... "Are you just going to break your arms pointlessly? Like Izuku?"

It was a miscalculation. He didn't know the pair of them well enough. That Katsumi Bakugo didn't back down, that she wouldn't tolerate anyone comparing her to 'Deku'.

And so, once again he swayed out of the way of her now one-handed assault. Her tenacity wasn't impressive anymore. It was just sad. "What's your plan for when that arm gives out?" he asked, leaping back to get away from the last large explosive slap she brought his way. While before she had kept up with him using her explosions to propel her, now she couldn't manage that feat. Not with only one arm. And as she continued trying to catch him with blasts he had already proven he wasn't bothered by, he noticed her 'good' arm starting to twitch. His eyes narrow. "You're not recovered from the battle training, are you?"

"Fuck you, you aren't either!" she barked at him, trying to swing at him again.

He halted her arm before it can get close. As she tried to push in and kick him he caught the leg too. Good flexibility, he noted, and surprisingly soft skin. "I am. My quirk is basically regeneration and improvement. Not only can I hear again, I can hear better than ever." He took in her panting and shaking form. "You, meanwhile, are tired, not thinking clearly and still dealing with the earlier fight on top of the damage you got in this one. So," with how he had her limbs trapped it was easy to pick her up despite her struggles and slam her not too forcefully into a tree, "Do you give up yet?"

BOOM!

The smoke cleared, Saiki's left ear rings from the noise but despite a momentary flinch, he didn't show any reaction, still holding her against the tree. "How about now?"

Her teeth grit so hard they might break. She couldn't deny it any longer. She felt like she was being outclassed left and right by the other students. She wanted to prove herself, prove she still deserved to stand at the top! So she picked a fight and fought stupid, in her own head the whole time. He even played on it, bringing up that fucking Deku!

"I lost... And to a fucking creep like you..." she ground out.

Saiki rolled his eyes. "It's almost like people in the top hero program in the country are strong or something."

"Fine. Now fuckin' let me go!" she demanded, right arm and left leg struggling in his grip. He let go of her arm but as she tries to push past him his hand slammed into the tree over her shoulder, pinning her against it with his larger body. "The fuck are you doing, creeper?"

He smiled down at her in that way she hated as he pushed even further into her personal space. "Getting my prize, what does it look like?"

"Your prize?" she asked, only to realise, the stupid bet he wouldn't shut up about. "Oh whatever, get the fuck out of my way, creeper."

"Huh, really?" he asked with a raised eyebrow and that damn smile. "You struck me as such a proud girl. I guess not if you'll just welch like that. Or did I break your pride that much?"

"Eat shit and die, creeper!" she snapped as a knee-jerk reaction to someone looking down on her... "What do you want."

His face got close enough to hers she could feel the warmth of his breath but she barely noticed it compared to the feel of his hand groping her chest. "Your virginity."

"FUCK YOU!" she shouted trying to shove him away to no avail. "Is this how a pathetic piece of shit like you gets girls? Has to beat 'em up first?!"

He grins at her, pulling back a bit. "Is that what happened here? Did I beat you up?"

"Tch!"

"Do you want to be the number one hero?"

"What the fuck does that have to do with this?!"

"Because it drives you. I like that. I like that passion. It reminds me of me, if in an angrier sort of way. So I want to take something from you. Something you can never get back. A loss that will drive you all the more, to push you to greater heights." His hand moved from her breast down under her skirt to slide his fingers over her covered mound. "If you want to, you can just say no," he commented lightly, drawing lazy circles over her pussy. "It just means you're the kind of coward who runs away from the consequences of her actions, that's all."

She hated him. That was what she realised in that moment. She hated his stupid fucking ponytail. That ugly smile. The condescension. They way even now he was taking liberties with her body as if he already knew she would agree.

She hated that he was right.

He vastly overestimated how much she valued something as stupid as her virginity. Like what, was she supposed to save herself for marriage or some dumb shit like that? Stay pure so she can land a good husband as if that fucking mattered? But... Even if it was something she didn't value, even if it didn't matter half as much as the creeper thought it did, he was still taking something from her. He still beat her. He was still looking down on her. And if she let this happen... Well he was right about that too. She wouldn't rest until she could kill him with her own hands!

She channelled all of the hate that she felt into her eyes as she fixed him with a glare. "Next time... I'll win." It was a promise she intended to keep.

"Well then," he answered with glee as his hands came together to unbutton her jacket and school blouse, "I'll look forward to next time too." As he pulled open her shirt to reveal her sports bra he was surprised she made no move to look away or cover herself, just continued to glare at him. The fire in her eyes only made him harder, made him want her all the more. He pulled up her bra and firmly groped and squeezed her tits. They weren't large, more of a size to fit comfortably in his hands as he massaged them, thumbs rolling over her nipples in a way that made her breath quicken. She could fight the feelings he was causing all she liked but she would end up enjoying this. He had plenty of practice and for him, practice made better than perfect.

One hand slid down her strong, well-defined abs to the hem of her skirt, then up and under it, starting to peel down her spats with the one hand before the other comes to help. He leaned towards her–

"Don't you fucking kiss me," she growled with deadly intent.

Fair enough. Maybe he would make that his prize for next time. Saiki admitted to himself that maybe he let his own desire for gratification get the better of him here. But he felt it might just have been worth it when he got a look at her pussy for the first time. "It's beautiful!" he exclaimed.

"Shut up..."

"It's so slim and tight, and such a lovely shade of pink!"

"Shut up!"

"I can't believe you're clean shaven–!"

"SHUT THE FUCK UP AND FUCK ME, CREEPER!" She didn't appreciate how he laughed at her while he unfastened his pants. "What's so fuckin' funny?"

"Oh, nothing," he said as his chuckles died down and he rubbed his painfully erect cock over her moist slit. "It's just so gratifying when a girl begs for it."

"WHO THE FUCK WOULD– Nnnnnnmph!" She hadn't been prepared for it. In the middle of trying to chew him out for his bullshit comment he had shoved his cock inside her! It caught her so off guard the moan escaped before she could bite down on it!

"Here's the thing," Saiki said conversationally as he started fucking her at a pace he would call lazy, "My quirk makes me better at things I stress myself doing. And since I got accepted to UA?" His pace picked up, getting more vigorous, starting to really work at stirring up her insides as he railed her against the tree. "Let's just say my dick has been thoroughly stress tested over the past three months." He leaned in over her shoulder. "I'm going to make you cum, Katsumi. Over and over. I'm going to make you cum so hard it won't matter how much you hate me, you'll want to come back for more."

"Hmn, hmn, hmn!" Katsumi bit down on her lip in a vain attempt to silence her moans and gasps but as his arms hooked under her legs, holding her up to thrust even deeper, she lost the battle. "Hah! Hah! You fuck! You fuck! I fucking– Ahhhhh!" She felt her insides clench, her muscles spasm across her body as it lit up with bliss from head to toe. It didn't stop! Even as the waves of pleasure ebbed his cock struck a certain spot and her body lit up all over again!

"Maybe next time I'll take your first kiss?" he continued to whisper as he sped up again, his balls slapping against her with the force of his thrusts. "Or maybe I'll have you suck me off, how about that? Have your first intimate act using those pretty lips be wrapping them around my cock? Don't worry, I'll still fuck you again after. Have to take care of your needs too. Won't that be nice?"

"I fu– Fu–..." She couldn't even string enough words together to curse him out anymore as her pussy gushed and squeezed around him again. At the same time Saiki couldn't help but wonder if those fluids were explosive too, not that he was dumb enough to ask the question out loud.

"That's what will happen. Unless you win next time, of course. After all, Katsumi Bakugo is strong, isn't she? No matter how good it feels she'd never lose to some creeper's cock would she?"

"Nuh... Nu-hnnn!" 'Stop', she whined in her own head! 'Stop making me cum!'

"She'll win next time and she'll never have to think about his cock ever again, or how right it felt to have his cum flood her womb!"

A yelp of panic exploded in Katsumi's brain! "No, don't–!" she tried to say but her limp and lolling tongue only formed a whimpering gurgle.

"Here it comes!" he grunted, driving as deep as he could inside her with shallow thrusts, hot bursts of fluid jetting out to stain her insides with his seed. It took a good twenty seconds for his balls to stop clenching, for his climax to run its course. Stress. An orgasm counted, who knew? By the time it was over Katsumi's inner thighs had partially been painted white and her spats hanging between her legs had caught some too. Pulling his cock free, he had a fun thought. Holding her up by the shoulder he pulled out his phone and took another glamour shot. Leaning her against the tree he did the gentlemanly thing and fixed her clothes up, pulled up her spats, pulled down her bra and buttoned her shirt even as she slumped down to sit against the tree, her legs gone completely numb. "Isn't this nice, Katsumi? You can wear me home!"

Looking at the sky as he got dressed he saw the sun had gotten pretty low. Juri was probably wondering where he was. "Well, that was fun. I look forward to round 2." He turned, waving without looking back as he walked away. "See you tomorrow Katsumi!"

Katsumi Bakugo, twice defeated, fucked into a puddle of her own fluids and his could only sit there and wait for the feeling to come back into her legs.

Next time. Next time she would win. And then she would make him pay!