Thank you deem on AO3 for the quirk idea of being unable to detect Kuro's presence. I'm going to keep it simple and call it Stealth
SnyperLife, I believe that was a misconception. Whenever I say couple, I almost always mean two, and it slipped my mind that it could also be seen as a few. Izuku was 8 when he first met Kuro, and the timeskip here lands Izuku at 14. I'll be sure to edit the first chapter. Thanks for catching that
Chapter 02: The Second Tenth
"You can't be a hero without a Quirk," Midoriya's idol, All Might, right there, shot down his dream. "Why don't you become a police officer? Being a hero is dangerous. Being a hero can be very dangerous." The scrawny man sighed and went down the stairs. Midoriya stood there, a blank expression on his face. Even if All Might didn't believe him, he knew he had someone who did. Black Lightning, otherwise known as Kuro Gisei, Number 7 Hero has been training his body and mind to become a hero. Midoriya followed his idol down the stairs and exited the building as he saw a crowd.
Midoriya wormed his way through to see his childhood friend, Katsuki Bakugo, now being known as Kacchan, stuck in the slime villain that attacked him earlier that day. Without thinking, Izuku ran up and plunged his hand into the slime creature before tugging as hard as he can, pulling out Kacchan.
"Oi Deku! What the fu-" Kacchan was cut off when the slime monster grabbed both Izuku and Kacchan and started to absorb the two as he started to laugh maniacally.
As Izuku's vision starts to be enveloped by sludge, he could hear a voice yell "DETROIT SMASH!" Izuku found himself free as All Might was there to save him.
"Fucking Deku!" Kacchan yelled at the boy, ignoring all the heroes standing around him. "I didn't asked to be saved. I don't need some quirkless loser looking down on me!" Kacchan stalked away, obviously mad before Izuku could protest.
"What were you thinking?!" Death arms ran over to the boy to scold him. "Do you know how dangerous that was?!"
"I know," Izuku said calmly as he looked the hero in the eye. "I don't regret my decision as all. I saw someone who needed to be saved and that's all that matter."
All Might looked at Izuku in a whole new light as the boy walked away, a proud expression on his face.
Izuku was walking home as he saw a familiar, scrawny man waiting for something, "Young Midoriya," All Might said, grabbing his attention.
"Y-yes, All Might-san?" Izuku asked, the adrenaline high already gone, so it was back to the stuttering. "W-what it is it that you need?"
"You know, those actions you did earlier. Even though you were quirkless, you did what the top heroes would do. Moving without reacting," All Might said. He looked at him, his black eyes filled with determination. "With a mindset like that, I'm sure you can be a hero. Meet me at the beach tomorrow morning."
Izuku woke up early that morning and leaving a note to his mom that he was going to train with Kuro. Of course it was a lie, but Inko has approved of Kuro years ago, as he assured her that this would be only beneficial to him. Speaking of Black Lightning, Izuku was really excited to tell him about the events that transpired, but he was nowhere to be seen all day.
Izuku saw All Might walking towards the beach as well. "All Might-san!"
"Ah, Young Midoriya," All Might said. He was in his scrawny form, as he didn't want to attract the press. "Let us walk to the beach. We need to start your training."
Izuku nodded silently. He didn't know what Kuro would say, but he hasn't seen him and Midoriya just figured he would tell the bulky hero later. To the young man's surprise, he saw the number seven hero staring off into the horizon. "Hey, little man," He said as he turned around. "Ah, Toshinori-san. I take it you're here to train my student?"
"Y-you know he's-" Izuku started but was cut off by Kuro.
"All Might's consultant," Kuro finished. "I've seen him a couple times while working with All Might-san. Anyways, I have some business to deal with. I'm still expecting to see you after school, little man."
Kuro walked over to the pair and put his hand on Izuku's shoulder and looks at Toshinori with a soft smile on his face. "I never expected you to take on a student. I'm trusting you with him, kay?" All Might nodded, and Kuro smiled wider as he walked off.
All Might looked at the man skeptically, but decided to ignore it for now. After all, he had a student to teach.
Five months later, it was time. The previous training that Kuro did with Izuku helped immensely, as Izuku's body was already well developed. As All Might hands Izuku his hair, he beams at him with that signature smile of his. "Be sure that no one learns that you got this power from me. There are a few people who know, but no one more should learn."
"Does Black Lightning know?" Izuku asked. Kuro was practically the cool uncle Izuku never had. Izuku wanted to tell him, but he understood the dangers of that knowledge.
"He does not," All Might simply stated.
After school, Izuku went to the beach to train with Kuro, as usual. Kuro was standing, staring at the horizon, just like that day 5 months ago. He almost never does that. He only did that when All Might started teaching him.
"Ano Kuro-san?" Izuku asked, causing Kuro to turn around. "Are you okay?"
"Yeah," Kuro said. "I'm just thinking about how I should help you with your quirk."
"H-how did you know I have a quirk?!" Izuku sputtered. He had only gotten his quirk today. No one should have known about it. Not even Kacchan, or even his mom knows about his new quirk.
"I have my ways," Kuro simply stated. "Anyways, that smash shit that All Might was teaching you? Don't do that. All Might was a prodigy with his quirk. Your body hasn't adapted to the quirk, so if you focus it on one spot and attack, you'll wreck your arms. Only use it as a last resort."
How did Kuro know so much about One for All? All Might said Kuro shoudn't even know about, much less how to use his quirk. Before Izuku could say anything, Kuro continued. "Try focusing the quirk on your entire body. Think of it as like a buff in a video game. Try to control it, though. No more than say, five percent. Any more as of now and your body will start to break under the power."
Izuku had a lot of questions, but decided to try it out. He concentrated on the power deep inside him, and focused on channeling it on his entire body. His body started to glow and green sparks started to crackle around him.
"Good, now try attacking me," Kuro said, his arms crossed. It wasn't uncommon for Izuku and Kuro to spar. Izuku dashed at Kuro, but was taken by surprise by the force of the movement, and flew a few feet into the water as Kuro sidestepped and dodged his attack.
Kuro snickered inwardly as Izuku dragged himself ashore. "You knew that was going to happen didn't you?"
"Yup," Kuro said, smiling. "Now we'll spend the next five months getting you familiar with your power at only five percent. No going further until I say so."
Izuku sighed and called for the power again, preparing to attack his mentor. "Alright, let's do this."
After a couple hours of training, Izuku laid on the ground, panting as Kuro stood over him, no small amount of pride on his face. "Good job, little man," Kuro said as he offered Izuku a hand. As Kuro pulled him up, his expression went serious. "One thing that I need you to do is not tell All Might of my knowledge of One for All. If he finds out now, then we'll probably get into a whole den of trouble that we don't want to get into now. I promise I'll tell him, but I'll do it when I'm ready."
Izuku nodded at Kuro, and the tall man smiled again. "Now, let's get you to a shower. You smell like saltwater and pain."
Izuku chucked slightly and punched Kuro's arm playfully as they started for home.
Five months later, it was time for the exam. Izuku was feeling confident about the exam. He had been training diligently with All Might and Kuro and managed to get to 6 percent Full Cowl as Kuro had dubbed it. Kuro was equally shocked and proud at the young man's progress, saying that it wasn't normal for a wielder of One for All to make such progress. Whenever Izuku asked about how Kuro knew things like that, Kuro would just dodge the question and change the subject. Izuku may be imagining things, but it seems that Kuro hits a little bit harder during sparring sessions where Izuku brings up the man's knowledge of One for All.
Izuku's musings were interrupted by a stray rock as he trips on it. He prepared himself for impact, but that impact never came. He opened his eyes and to his surprise, he was floating.
"Release!" He heard a female voice before he fell, landing on his feet. "Whew! That was a close one! Are you okay, there?"
Izuku turned around to see the one thing he feared the most. A girl. Izuku's face instantly went red as he started to stammer. "Y-y-yeah! T-thanks for saving me there."
"No problem!" The girl beamed, practically oozing positivity. "My name is Uraraka Ochaco! What's yours?"
Relax, little man, Midoriya can hear Kuro's voice in his head. This was something Kuro had taught him along with training his body. How to help his social anxiety. Girls are people too. They're usually very nice. There's no reason to be scared of them.
Izuku knew that it as at least partially a lie, if Aunt Mitsuki had anything to say about that. He took a deep breath and smiled. "I-I'm Midoriya Izuku," He said, returning a smile. "It's a pleasure to meet you."
Izuku was trying his best not to cover his ears. Present Mic's speech on the exam was… loud to say the least. Izuku could barely think, much less muse and mutter as he usually does. It was a blessing in disguise, though, as Uraraka had insisted on hanging with him because she didn't have any other friends. It wasn't that Izuku didn't like her company, as she was a great person, it's just that Izuku found it a miracle that he hasn't passed out yet after such prolonged contact with a girl.
"ALRIGHT! ARE YOU READY?!" Present Mic shouted to the crowd of teenagers as a loud cheer could be heard from the examinees. "ALRIGHT, THEN! START!"
Meanwhile, the staff watched in a designated area to examine the kids. Nezu, All Might, Lady Midnight, Eraserhead, and a few others were there, examining the students dashed off.
"Hm, this Midoriya kid seems quite interesting," Nezu states as the screen focuses on Izuku, who seemed to be rescuing participants in danger as well and destroying the robots. "Do you think he knows about the rescue points?"
"I don't think so!" All Might states. "I see it in his eyes! That boy is saving those kids because he wants to!" Of course it was complete bullshit, but All Might knew his successor. He would rather just save people, points be damned.
Before anyone could say anything further, the door opened, revealing a tall, muscular man with black hair and black eyes. He work a black, one piece uniform and a neck guard. He was known as Black Lightning, the number seven hero in Japan.
"So, am I late?"