It was rare for Katsuki to feel genuinely amused, but when he was, it filled him with a sort of warmth that he wouldn't trade for anything. His natural state was one of tense preparedness, waiting for some sort of attack, verbal or physical, so that he would never be caught off guard. He had gotten good at dodging slaps and shoves at home and he could return fire with nasty, targeted insults with the best of them… but every time he was struck by one, it felt like a personal failure. To avoid feeling such things, Katsuki was always on guard… but as he watched Shiv absolutely manhandle Izuku in the otherwise unoccupied classroom, he couldn't help but relax and simply take it in. The sight had even caused him to smile for the first time in as long as he could remember.

Shiv was quite tall- the tallest in his class- and quite literally towered over Izuku, rendering him an easy target… and yet the younger boy had yet to land a hit upon him. The few times the two had made contact, it was for the furry heteromorph to turn aside a blow or catch Izuku's fist and use the momentum to throw him aside. Izuku had ended up on the floor more than once in the span of only a few minutes, accruing bruises and bumps without Shiv throwing a single direct blow. The embarrassment and frustration had spurred Izuku to clench his teeth and growl as he stood up once again, a bit of green energy crackling around his fists as he did so.

"Upset?" Shiv inquired, remaining ever calm as he kept a wide stance, his arms forward and fingers spread. It was an unfamiliar technique to Katsuki, but one that he intended to ask about later. "I can see One for All passively modifying your baseline strength, whether or not you choose to engage it. I should have no chance of standing up to you… assuming you know what you're doing. Exhausting yourself by doubling down on your strength will do nothing when your technique is so poor. The issue isn't how hard you're hitting. It's that you're not hitting."

Izuku made another noise of frustration and disengaged the active part of One for All's strength enhancement, already feeling a bit of fatigue in his muscles. The activation had clearly been a mistake… and one that the boy had a feeling he was about to pay for. All the same, he charged in once again, dipping his upper body backward at the last second to try to fake out his mentor. Instead of swinging or remaining neutral, the upperclassman leapt forward into a full-body tackle, securing his arms around Izuku's torso as he brought the smaller boy to the ground. Before Izuku could really react, Shiv twisted the younger student's arm behind his back and drove a knee into the back of his spine, earning a cry of pain. Green sparks once again jumped from Izuku's body, only for Shiv to roll off the boy and over his head, landing a hard kick to the skull as he went.

"Sloppy," the man accused as he dusted off his fur while rising to stand. "Impulsive, brash, and unwilling to take advice to heart. Stand down. I'm done with you for today."

Izuku hissed and unclenched his fists as he stood, looking quite obviously furious. Katsuki's perpetual smirk only pushed him further into anger, and as the energy around his fists dissipated, that annoyance turned to a noise of pain.

"Damn it…" Izuku said quietly as he shook out his hands. "How are you so fast? Why was that so easy? I'm supposed to be…"

"Paying attention," Shiv finished for the boy as he patted his fingerless gloves together twice to dust off his hands. "And now, you're a sweating, seething mess. Go and clean yourself up and get ready for your first actual class. Professor Aizawa will be accompanying you all through your schedule today."

"But…" Izuku started, though at Shiv's glare he thought better than to question the order. "…okay. Sorry…"

"You will be, if you keep this up," Shiv threatened as he turned toward Katsuki. "And you. This is how you taught him to fight?"

Katsuki's smug expression quickly faded, and he flicked his eyes to Izuku as the other boy bowed and left the room.

"…no. I don't just rush in without a plan, and I don't over-commit to attacks that are a gamble."

"You just told me what you don't do," Shiv explained as he folded his arms over his chest. "But not what you teach. There is an art to it- one that most don't understand or respect. Showing him what you do without thorough explanation of theory will lead to subpar execution. There is a possibility he is a terrible student. There is an equal possibility that you are a terrible teacher. Perhaps it is both. Only one way to find out."

"Figures," Katsuki muttered as he took a deep breath and raised his fists. "Can't use my Quirk in here. We taking this outside?"

"…do you think I would gain any valuable insight fighting you in the next five minutes?" Shiv asked, his tone filled with condescension. "You have places to be, as do I. We'll be meeting tonight in the training city. Give me your phone, and I will send you a time. Don't be late."

Katsuki reached into his pocket and produced the device, handing it over without resistance.

"Sure. Is Izuku going to be there, or…"

"Do you want him to be there?" Shiv asked rhetorically as he put his number into Katsuki's phone. "I don't know what's going on with the two of you beyond the obvious, but I was under the impression that you would rather train alone as much as possible. I am fine with that arrangement, though I do want you there for him occasionally so that I can see what you have and haven't taught him."

"Not like I've got a choice," Katsuki replied with a shrug as he watched Shiv's thumbs dance across the tiny screen. "And if you say I do, and I could tell him to fuck off… that's not a realistic option. One for All is the most important Quirk in Japan. Making sure he takes care of it and doesn't misuse it is basically a job. I didn't ask for it, but he needs someone to keep an eye on him."

"And so, the burden falls to you," Shiv replied as he tossed the phone back to Katsuki and approached. "It seems the country is lucky you care what happens to it. Shirking your role in all of this would be all too easy. It's a wonder that the Quirk didn't go to you instead, based on what I've already seen of his attitude."

"Don't go there," Katsuki warned as he caught the phone and slipped it back into his pocket. "Not something I want to talk about."

"I figured. Give me your hand," Shiv ordered, offering his own.

"What…?" Katsuki asked, keeping both in his pockets as he considered taking a step away from his mentor.

"Hand," Shiv repeated, keeping his out between them. "Don't waste my time, Katsuki. I have a neutral to favorable view of you at the moment. Not so much for Izuku. I, too, will be training him out of a sense of obligation, though not for Japan in particular."

"He's…" Katsuki started, feeling a little bad as several descriptors jumped to the forefront of his mind. There had been some good times between them, and the situation was a rough one to navigate… no matter how much he felt like his friend was a complete idiot. "…frustrating."

"I can already tell. Hand," Shiv repeated, sounding bored. "Do you want to benefit as much as possible from my abilities and experience, or not?"

Katsuki finally relented, slowly extending his hand toward Shiv. Rather than shaking it, Shiv seized the limb by the wrist and raised it closer to his face in order to examine it. The glow in his eyes intensified as he seemingly studied Katsuki's skin, tracing his gaze up along the palm and to the wrist.

"Remove your uniform jacket and roll up your sleeve," Shiv ordered.

Katsuki fought off the urge to ask why, and instead did as he was told while Shiv momentarily released his grip. Upon rolling up his sleeve, he began to feel a bit of panic. Just how much Shiv could interpret was still a mystery… and there were some things about him that he didn't want known by anyone, including a mentor.

"...you've permanently damaged your skin, though not extensively," Shiv said softly as he once again held the boy's wrist and narrowed his eyes. "The pores upon your palms are unnaturally large, likely a byproduct of utilizing your Quirk at its extremes."

"Yeah, well… I… that's part of training," Katsuki explained. "I put my hands in hot water a lot to open them and let more sweat through at once. Makes for bigger explosions. I was told it's not a big deal."

"It's not, on its own," Shiv agreed as he furrowed his brows. "But you're also doing light nerve damage, from the repeated exposure. Your hands ache often, do they not?"

Katsuki nodded slowly, following Shiv's eyes as they moved beyond his wrist and to his forearm.

"They ache, they burn… I'm used to it. If I use my Quirk a lot, they sting for a long time. It sucks, but that's how it is. It's... whatever. I can handle a little pain."

"You're overdoing it," Shiv accused. "How often do you train with this hot water method?"

"Daily," Katsuki answered, flexing his fingers.

"Well… stop it," Shiv ordered. "Start listening to your body and limit how often you do it, lest you cause lasting damage that's more than just annoying."

"I wasn't allowed to."

Shiv looked up from Katsuki's arm to try to meet the boy's eyes, only to find him looking away.

"…you've broken the bones in this arm, as well. More than once. Or perhaps, you haven't broken them, have you?"

Katsuki sucked in a breath, keeping his eyes on the far wall.

"…don't want to talk about it. Also don't want to talk about anything else on that arm. Are we done?"

Shiv looked back down, studying the other subtle feature he had noticed. A long, singular scar that had faded over time ran from his wrist down toward the elbow, where it suddenly curved and then ended in a jagged zig-zag with a deeper, raised wound at the end. The heteromorph could see traces of the metal still embedded in the wound, and he knew exactly what it meant. He also knew that pressing Katsuki on it would be unwise for their relationship moving forward.

"As you wish," Shiv said with a sigh as he let go of the arm. "Though, should you ever wish to discuss such things… I would be willing. You do not strike me as the type to go to many with your problems. Neither am I. Easier to handle it alone due to the threat of another misunderstanding, yes?"

"Yeah. Whatever, alright?" Katsuki said as he rolled his sleeve down and swiped his jacket off the nearby desk. "Don't try getting all friendly."

"I was like you, last year," Shiv commented with a dismissive wave of his hand. "In many ways, I still am. Not to the same degree, but… this is a conversation for another time, clearly. Don't be late to class. We'll talk tonight, with fists, words, or both. Just make sure that you do have someone you can rely on. If not me or Izuku, then someone from your class, yes?"

"Yeah. I get it," Katsuki said flippantly as he finished pulling on his jacket and headed for the door. "Thanks for the concern or whatever. Just… back off a little. I've got people. See you tonight."

Shiv watched as Katsuki offered a halfhearted wave and retreated from the classroom, leaving him alone with his thoughts. With a sigh, the heteromorph pulled his eyepatch from his pocket and slipped it on, feeling conflicted.

"…I suspect that you do. More than you know…"

Author's Note:

Back to the workshop next time, and then, the classes begin…

-RD