Katsuki stood in Gym Gamma with a surprisingly large audience. Nedzu agreed to let him, Izuku, and their families come to U.A. that Sunday since the campus would be relatively empty except for some administrators.
The principal and All Might seemed to have invited a couple other people, likely the others that All Might said knew about One For All. As much as Katsuki didn't like doing people stuff, he supposed introductions were in order now that everyone was gathered.
He bowed to the two unknown people – a shorter elderly man in what was clearly a hero costume and a taller, lanky man who felt familiar to him – in a show of respect.
"It's nice to meet you. I'm Katsuki Bakugou."
The two men bowed in return as Katsuki straightened back up.
"I'm Sorahiko Torino," the elderly man said, "I trained the blonde oaf with One For All when he first got the quirk as the hero Gran Torino. Good to see you young brats still have manners."
The taller man spoke next. "I'm Mirai Sasaki, All Might's former sidekick Sir Nighteye."
Katsuki couldn't help the grin that spread across his face at the confirmation of his suspicion.
Nighteye continued as he stood straight, adjusting his glasses with his large fingers while he walked in Katsuki's direction. "I'll be honest, I'm not here for goodwill. I'm here to see how hard you fail trying to use One For All."
"Eh?!" Katsuki shouted, stomping right in front of the pro. "What the hell, four-eyes?"
"How dare you?!" Izuku stepped up angrily behind Katsuki.
All Might spoke up in Katsuki's defense. "That's enough, Mirai! I told you that Young Katsuki is my successor, and that's final! Young Togata is a fine boy, but I've given One For All to young Katsuki, and it will stay that way!"
"Mirio is a much more suitable candidate than this child, All Might, and you know it! I've been training him to have the skills you lacked!" Nighteye countered, taking his eyes off Katsuki and his best friend.
"One For All was my quirk, Mirai! It was never your choice of who it went to, and now that it's in Young Katsuki's hands, I'll be damned if you try to make him feel unworthy!"
Reaching a hand out to use his quirk, Nighteye spoke again. "How could an arrogant, brash brat coming out of middle school be worthier than a groomed young man properly trained to hand–"
"Shut your fucking mouth!" Came a bellowing screech.
Turning to face the source, those gathered find a trembling Izuku. Ozone fills their nostrils as his pants permeate the sound waves. His clothes float in the current that wasn't there previously, glaring a burning hole through Sir Nighteye's shocked gaze. His hair stood on end, and Katsuki noticed his eyes had changed from kind emerald green to scorching gold.
"Ignoring what you said about literally grooming a fucking kid for One For All," Izuku started to rant as Nighteye flinched, "I will not let you shit-talk my brother like that."
"And who are you to criticize me, ki– GHOU!"
Nighteye was cut off by a sudden pain in his stomach that carried as he was mercilessly sent rocketing against the nearby wall. He landed on his hands and knees, blood trickling from the corner of his mouth as he desperately tried to catch his breath. Hearing a high-pitched noise above him and seeing the shadow cast down on him, he looked up to see the same boy who had viciously called him out a mere moment ago. The boy knelt down to get right in Nighteye's face as the rest watched in shock.
"Katsuki may be brash, but he has a heart of fucking gold. All Might wouldn't have offered the power to either of us if he didn't confirm we are worthy first."
Nighteye tried to interject but was again cut off.
"I really feel sorry for whoever you decided to groom for One For All, considering they probably don't even know you were using them like a fucking tool. One For All is not, and never was, your power. It was All Might's, and now it's Katsuki's, and I'll be damned if you try anything to insult him or take the power from him. Do I make myself clear?"
Nighteye stared with wide eyes in complete shock. This boy had the gall to not only question but strike a well-respected hero on U.A.'s grounds, right in front of multiple heroes and U.A. staff. This kid had to be trouble, he thought.
He reached a hand out, feigning weakness as he moved to try and activate his Foresight quirk on the boy, only for the boy to disappear and reappear out of his reach.
The only reason he considered his action could've been a mistake was the sheer malice that began emanating from his form. An almost imperceptibly quiet, animalistic growl escaped from his grit teeth, his faint crackles of electricity arced along his toned muscles, and his eyes narrowed in wrathful disgust.
"Don't. You. Dare. Use your quirk on me or Katsuki, Nighteye." the teen snarled. "You have no right to use it on innocent people without their permission."
Nighteye finally got to his feet and made to move toward the greenette before he felt All Might's hand press to his chest. He looked up, shocked by the look of pity on his former boss' face.
"Mirai, I think it's long past time for you to leave." He said sternly.
"But–" He tried to reply, offended that All Might would rail against him instead of the kid that assaulted him, but All Might beat him to it.
"Young Izuku, albeit aggressive, hasn't said anything incorrect. Despite how pure your intentions may be, you've admitted to grooming young Togata for my quirk. That's disgusting. Young Togata should be his own hero. I don't expect young Katsuki to be me, and One For All is his now."
Nighteye just grit his teeth, refusing to back down despite knowing he was fighting a losing battle.
That became more apparent when Nedzu spoke up. "I must say this revelation is indeed distressing! I'm afraid I will have to rescind your approval to take on students of U.A. for work studies and internships, effective immediately. I will be recalling Mirio Togata by the end of the day. I suggest you leave the premises, Nighteye. You are no longer welcome."
Nighteye tried multiple times to interject in the middle of Nedzu's speech but failed. He whipped around and stormed out as everything set in, but not without his last two cents.
"You're going to regret this, All Might. This boy will not be a worthy successor like Mirio is. You'll see eventually."
Everyone stood silent for a few moments until Katsuki and All Might remembered the raging half-Saiyan teen in the background.
"Hey, 'Zuku, you good?" Katsuki rushed to his friend's side.
"Yeah, yeah, I think so," Izuku growled, "I'm just struggling to calm down…"
If that wasn't true, then truth was relevant. Raw, unfocused energy poured from Izuku as the electricity refused to subside. He was twitching and shaking in place, trying desperately to relax.
"Focus your mind, Izuku," Hisashi instructed in a calming voice. "Nighteye has left. His energy is distancing itself. Katsuki is still here and unharmed, focus on his presence.
Izuku closed his eyes after a brief second and took a deep breath. He focused his energy on sensing Katsuki, and it instantly had an effect. Feeling the immense power of One For All coursing through him took a surprising amount of concentration as if focusing on nine different people, including Katsuki himself. After a minute, he released his focus and opened his eyes. He felt much calmer now. His father's advice worked perfectly, as expected.
"Okay, I'm good. Let's test out One For All now."
Katsuki nodded as both boys looked expectantly at All Might.
"Yes, I believe that's best. I don't wholly approve of your actions, young Izuku, though I understand why you did what you did."
"Yeah, I'm sorry, I just lost it for a bit there."
"I understand, but controlling your temper will be crucial to your future as a hero. Now, come over to this cement block, young Katsuki."
Katsuki nodded and walked in front of the block All Might directed him to. "How exactly am I supposed to activate it?"
All Might tripped up for a second, coughing into his fist. "I-I'll be honest, One For All came naturally to me. I never had any trouble calling on it and using it. It might've been because I was born quirkless, though…"
Deciding to save the "born quirkless" bomb for another time, Katsuki grunted with the little help he received. "I guess the best start would be trying to feel it out?"
"I think that's a good start, Katsuki." Hisashi praised.
The blonde nodded. "You said One For All is an energy stockpiler, right, All Might? At least kinda?"
All Might nodded an affirmative, confused as to where he was going with it.
"Maybe I need to treat it like it's ki…" He said to nobody in particular.
Katsuki closed his eyes and began taking deep, full-body breaths, focusing on his core. He let the thrumming energy of One For All flow from down at his toes to the top of his head and back again. With every breath he took, One For All came more easily to the surface. Instead of feeling like a bomb ready to blow, it now felt like the ebb and flow of a forceful ocean wave. He could tell trying to access more than 10% of the power would lead to the wave crashing without control, so he only summoned 8% to test the waters.
Opening his eyes and asserting his control over the quirk, he raised his arms above his head and struck a pose not unlike a horse stance. Doing so, he generated a sizable air current that blew in all directions, stunning everyone save for Izuku and Uncle Hisashi. He looked down at his arms, noting the orange crackles of lightning arcing along him, similarly to Izuku's white lightning.
"How does that feel, Katsuki? Can you move?" Uncle Hisashi asked.
Katsuki nodded an affirmative, taking a couple steps back and forth to demonstrate.
"How much of One For All are you using?"
"About 8%, Uncle Hisashi."
Both Saiyans' eyebrows raised in surprise.
"So the power is exponential…" Izuku muttered aloud. "I can't feel the full depth of the power since you haven't used enough, but I can tell it's already greater than All Might had in his prime." Hisashi hummed in agreement with Izuku's statement.
Katsuki sported a feral grin as he suddenly spun a roundhouse kick into the cement pillar, causing it to break apart and fall from the point of impact. "This feels amazing!"
Izuku chuckled at the antics.
"How about you see if One For All powered up your explosions?" Gran Torino suggested.
Katsuki shrugged his shoulders and walked over to another pillar nearby. Wanting to test a theory, he powered down and held a hand out. He again focused inward, feeling out One For All. Instead of calling upon it to envelop his body, he willed it to flow through his arm and out of his sweaty palm, charging his Explosion quirk.
As the nitroglycerin-like sweat ignited, rainbow sparks filled his hand before a massive explosion shattered the pillar and sent Katsuki flying backward with a grunt of surprise.
Thanks to his training with his uncle, he managed to break his fall and get back up quickly, only to be hounded by Izuku and All Might, with Recovery Girl trailing behind.
"Are you alright, Kat?" Izuku asked with concern on his face.
Katsuki grunted, examining his arm, which was now coated with bruises. His palm was a sickly purple, and his fingers only slightly less so. Not quite broken, but not far from it. "Note to self: don't focus One For All into only explosions just yet."
"I'd say so." Recovery Girl quipped. "You're lucky the blonde oaf had the foresight to do this here where I could supervise. Let me see, dearie."
Katsuki acquiesced, letting the elderly hero take hold of his arm. She puckered up and pressed a kiss to his palm. His entire arm glowed as the bruising and pain subsided, followed by a wave of exhaustion forcing him to shake his head to keep from stumbling. U.A.'s nurse pulled out a Pez dispenser and gave Katsuki some gummy candies.
"These will help you recover your stamina. I'd say only one more test before we wrap this up, understood?" She asked sternly.
"Yes, ma'am," Katsuki replied, thoroughly cowed. He may be cocky, but he knew one thing: nobody fucks with the white mage.
He walked to another pillar, the last pillar he would destroy until he made it into U.A. properly. He powered One For All up, this time going to 10%. He flexed various muscles and shadow-boxed for a few moments to ensure he could handle the power. He could, but he felt minor strain, so he should probably keep it to 10 or less.
10 should be enough, though. Once again, he held out a hand – the opposite one this time. He refused to keep destroying one part of him if this failed – and summoned both One For All and Explosion in tandem. The same rainbow sparks ignited, but the explosion was more subdued. He could tell it was stronger than explosions at the same exertion without One For All but weaker than the wild one before. It still shattered the pillar, but there wasn't any negative blowback save the minor strain from his limit of One For All.
He bore a toothy grin as he growled in pride, fist-pumping with the same hand. "Hell yeah!"
As Izuku ran in and tackled his brother with a hug, Hisashi mused to himself loud enough for the others to hear. "It seems that One For All should be used similarly to ki: spread across the body to reduce strain and only focused into one part for stronger and more 'desperate' attacks. With his Explosion, I believe a similar phenomenon is at play. Focusing One For All into an explosion, even if he uses the same percentage, focuses the energy into too small a point for him to safely use. It could be a good last resort if he needed it to survive. I suspect that training both Explosion and One For All might increase his natural resistance enough to use the more intense attack." Recovery Girl and Nedzu agreed with nods while everyone else just stared at the impressive on-the-spot analysis.
"Please don't make a habit of damaging yourself just to use stronger moves, though. It would be unwise." Nedzu stated while Recovery Girl and Gran Torino waggled their canes threateningly in Katsuki's direction.
"O-of course, sir." Katsuki said.
"Very good!" Nedzu replied. "I believe that will conclude our testing. I hope to see you and your friend in the hero course in the coming school year, boys! Don't forget to keep up with your studies!"