Terasaka Ryouma hates Korosensei. He hates this class and their assassinations. He hates how much everything has changed, but above all else he hates that quirkless Deku that won't stay in his place.
Shiro knows Tersakak's hate makes him blind and easy to control.
Class 3-E. The end class. The bottom of the barrel. Ryoka had thought he'd find people like him down here. People that weren't concerned with grades or appearances. People he could have fun with. Instead of a stagnant place where he could force his way to the top of the hierarchy, he found a place of growth. Everyone was doing better under that monster's tutelage. He'd at least hoped the quirkless loser would stay in his place, but even he kept climbing. His grades had risen steadily with Korosensei's help, and he even seemed to be growing a spine.
At least, he assumed that's why Korosensei had been on his ass before he even managed to move in the Deku's direction to remind him of his place after he jumped up to place 72nd in the school, compared to his old rank of 164 and Ryoka's current rank of 159.
Of course, Korosensei hadn't liked anything Ryoka had to say about the matter and sent him out doing random shit in the woods for a week after that. And then doubled down on his lessons to get him back up to speed with the rest of the class. As much as Ryoka hated him and tried to ignore the damn octopus, he still wound up actually learning.
Which is why when that Shiro bastard gave him a plan and some money, he went with it. Destroying the pool had been a blast, and the added cash didn't hurt. Watching the other students despair their precious pool had been well worth it, too.
Of course, the damn quirkless shit had to go and start thinking again, giving Ryoka and his friends a weird look rather than despairing like the rest of the class. "The hell are you looking at, Deku?" he snarled, stepping forward to grab the flinching boy by the front of his shirt. "Do you think we're the culprits or something? What is that going to get you?"
Deku only had the grace to look scared for a moment before getting this look on his face and opening his mouth like he actually had something to say.
"You're absolutely right," Korosensei interrupted. "Looking for a culprit isn't going to do any good, so let's not worry about that." And just like that, the pool was fixed. "There you go! Good as new! Please, go play like this never even happened."
… Ryoka hated that octopus.
He continued with the plan, even if things kept falling apart. Even if his friends, Taisei and Takuya and Kirara, were getting into this monster's lesson plans.
It would work. It had to work. The octopus would be dead, and everything would go back to normal. They would have a normal teacher, and everything would be the way it was supposed to be.
Only the rest of the class wasn't willing to listen to him. Go along, maybe, but not listen. Something to do with him not helping out with their assassination attempts.
"You'll do what I ask, won't you Deku?" he said, pushing the quirkless brat against the wall where he'd cornered him.
"No, I won't," he growled back, "and don't call me that. It's not my name."
"You think you get to tell me what to do? You're nothing."
"If I'm nothing, I'd hate to know what you are." Deku glared harder. "If you won't respect me, I'm not going to help out, no matter what Korosensei says. I'm going to stay here, and when you come back all disappointed because you failed, I'll be waiting for you. I sure as hell am not going to waste my time on the half assed plan you have cooked up. Seriously, how are you planning on getting him in the water? He's not going to do it just because you asked nicely or waved a gun in his face."
"You little-"
Deku slammed a fist in Ryoka's stomach, then quickly body checked him to the side and knocked him to the ground, dancing out of reach before Ryoka could react. "I'm not some little kid you can pick on anymore. I'm not gonna let you, or anyone else, pick on me just because I don't have a quirk. I can more than look after myself." Deku stormed off before Ryoka could recover.
Ryoka growled to himself and pulled himself up. He had enough self-control and self-respect to not charge the smaller boy's turned back before he disappeared around a corner. Barely. It didn't matter anyway. The plan didn't need anyone as useless as him, and that was one less person to split the reward with.
Izuku heard the explosion and knew Terasaka had done something stupid. How stupid he couldn't tell just yet, but it looked like he was going to go back on his word just to make sure the rest of his classmates were fine. Curse his heroic heart.
When he reached the pool, he realized just how much he had underestimated Terasaka's bullheadedness. The pool was completely empty and the dam Korosensei had built to make the pool was gone, bits of rubble littering the ground near where it had been.
In front of him, at the poolside, was Terasaka and Karma-kun. "This wasn't your plan at all," Karma-kun said. "Those two completely used you."
"I'm telling you," Terasaka yelled, hysteria taking over his voice and face, "this ain't my fault Karma-kun! The ones who set this up are the real bad guys! And everyone getting carried away by the water. It's all because of them…"
"Don't pretend you did nothing," Izuku hissed, causing Terasaka to jump and spin to face him. "You took credit for this plan. You called it your own and lead everyone astray by letting them believe someone as incompetent as you was pulling the strings. If they'd known who was really behind this, I doubt anyone would have listened to you." He glanced at Karma-kun for conformation.
Karma-kun nodded. "Shiro-san and Itona-kun," he said, by way of explanation. "You're lucky the target moves at Mach 20," he said, icy calm, "or you'd be guilty of mass murder. You got carried away, so how about instead of pointing fingers, you do something to fix it." He began making his way down the slope, following the small bit of water towards their classmates. Izuku shot Terasaka a burning look and followed. Even if Terasaka wouldn't think of something either he or Karma-kun would.
They arrived to Shiro-san monologuing. It wasn't much, just listing off weaknesses he'd taken advantage of. Nothing overly useful, thought Izuku made note of what he said all the same.
"He can only manage so much with the water as a handicap," Kataoka-san said.
"It's not just the water," Terasaka said as he stepped out of the underbrush and onto the cliff face as the fight rang out below them. "It's because he saved you guys. Take a look above him."
Sure enough, there were students still within reach. And if Hara-san's branch broke… it wasn't looking good. The class rambled on for a little bit, while Izuku watched the fight go on. As much as he could watch a fight faster than the speed of sound. It didn't take long for the rest of the class to figure out what Terasaka had been up to, and for Terasaka to confess his roll. "Guys with no drive like me are destined to be manipulated," Terasaka said. "But you know what, I want to choose who's gonna pull my strings from now one. I've had enough of these guys. I don't care about the reward money either. Karma-kun, Midoriya, I'm all yours."
Izuku's head jerked up at the sound of his name. As much as he'd been listening, he didn't expect Terasaka to involve him, much less actually use his name. He could see some of the other classmates were just as surprised as he was, but only a few that knew enough to realize it was weird. Izuku shared a glance with Karma-kun. "He's all yours," Izuku said. "Tell us what to do to clean up his mess."
Karma-kun gave him one of his signature looks. "Are you sure you want to go with my plan," he purred. "You might just die."
"I'll do it," Terasaka said, striding forward. "I can get it done."
"Even though I haven't told you yet?"
Terasaka stopped and sputtered.
Karma-kun clapped his hands. "I've got it!" he said, his voice dripping with false cheer. "Let's forget about rescuing Hara-san!"
What. That was…
Terasaka exploded on the snickering Karma-kun. Okay, so that was just to get a reaction out of them. Fine. Although…
"You said you wanted Karma-kun to take your strings, Terasaka," Izuku reminded him, "so while I'm glad you've learned to question things, Hara-san is right where she needs to be. Do what he says."
Terasaka huffed but shut up and listened while Karma-kun gave a swift dressing down for wearing the same shirt two days in a row, among other things. Eventually, Terasaka got huffy again and demanded instructions, but things went smoothly after that. Terasaka even followed his instructions to the letter. He antagonized Itona-kun and Shiro-san and took the hit exactly like he was told, making the opening they needed to let Korosensei save Hara-san and jump down to help level the playing field a bit themselves.
Things settled down quickly after that. Shiro-san and Itona-kun retreated, Hara-san had some words for Terasaka, but the class quickly returned to normal. Well, almost. Normal would be Terasaka still being angry and isolated from the rest of the class and hating everything about this whole mess. And everything about Izuku.
At least someone learned something from this.
Okay, quick note. No, Terasaka isn't magically "better" now. In the original, he kinda is, but the original isn't addressing any kind of bigotry. He has figured out that Izuku isn't bellow him, same as he suddenly figured everything else out with the class and Karma, but he sees Izuku as the exception, not the rule. Put him in front of another quirkless person, and it would be back at square one.
And no, Izuku hasn't magically forgiven Terasaka either. He can get along with him, but it's going to take a while before they can be more than just civil to each other. That's part of why I had Izuku step back and let Karma take over instead of involving himself too much. He'd rather keep his distance.