A/N Thanks for your reviews and support. I was not expecting to get any hype on this crossover. Imagine my surprise when I got TWO reviews. I'm so happy. Thank you both.

adislt: thanks for your review, my friend. Honestly to me, it looks white so that's how I describe him.

ZonZus: thanks for your review, my friend. Talking with you has given me a ton of ideas. I will try to give more to the chapter. Hopefully, you will continue to enjoy it.

Izuku's POV

His ki ran rampant through his veins in anger. His reserves of purified ki reacted to his anger. Sparks began to fly off his body.

It wasnt often that his anger grew out of control. Bakugo was the perfect tester of his patience and control. He constantly put the slightly younger boy down.

Izuku had only once lost control with him. It was right after he began training with Yoochun.

One day after school Bakugo had cornered him behind the main building with his goons. They began spouting how useless he was without a quirk. What if he really wanted to be a hero he should just die.

Even at the age of 7, those words had cut deep. Izuku had been carrying with him a darkness that rivaled those of an adult.

In his anger, he lunged at Bakugo fully intent on punching the boy. It was the first time he had used his purified ki.

Yoochun had helped him in building up his reserves so that if he was attacked he could defend himself. That did not include defending himself against normal kids. Only Murim something he would learn later.

Lightning fang had it landed could have thrown Bakugo into a coma. Whether he woke up or not would depend on two factors. Strength of the ki used and whether or not Yoochun used Thunder Break.

Just before it would have hit the white-haired bully Yoochun had stepped in. He blocked the ki attack and sent Izuku into the wall of the building. After threatening Bakugo with his ki presence he sent the older boy on his way.

Leaning against the wall Izuku questioned why he had been struck. That he was only defending himself against a bully.

Yoochun's next words struck deep within his soul, "Brat! Using your full power against someone who has no ki training makes you no better than him. Yes, you should always stand up for yourself but attacking someone who has no reliable way to defend themselves makes you the bully. So don't use your ki to fight these kids. Use your head. Be the better of the two. If you want to be a hero show them your courageous heart."

His master had been right that day. Even using unpurified ki against Kaachan could have seriously injured or killed the other. Until they started at a hero course it wouldn't be fair to use his ki against the older boy.

Along with his ki training, he learned the basics of different martial arts. Jujitsu, Judo, Taekwondo, boxing, and kickboxing. He threw himself into each one learning as much as he could as fast as he could.

With it, he learned control over his emotions. This made controlling his ki a lot easier. It also began to have changes to his body. Fat burned away into muscle slowly but surely. As his body could handle more stress it could also handle more ki.

Every day he worked towards being a hero. Now Kaachan was stuck in that villain. By the looks of it, it was a liquid villain. One that could not hold a shape without some form of host.

Heroes new and old were on the sidelines. They realized their quirks were not meant for fighting this villain. All they could do was stand aside and wait for another hero with a more suitable quirk to appear. Or...

Flashback

Lightning coursed up and down his arm. His reserves could only last for so long. By using up every bit of his reserves he was expanding how much ki he could hold at once.

It was only three months since he began his training. Yoochun had high expectations of him. Every part of him wanted to live up to the expectations.

The dark-haired man with bright blue eyes was the first person to truly believe in him. His mother didnt think he would be able to become a hero. Yoochun believed that he could if he could learn to use his ki.

When the lightning dissipated he was left breathless. That was the third time that afternoon he had run out of ki. Taking a deep breath he pushed on the pellet dispenser in his belt.

Yoochun was friends with several masters in the medical field. Those being naturally inclined towards the lightning element have less ki at the beginning of their training. All the groundwork has to be started from practically nothing.

The pellets in the dispenser were made of unpurified ki. At its current dosage, it would completely fill his reserves. On the other hand, if Yoochun was to take one of Izuku's, then it would barely give him enough for a single attack.

If Izuku was insane enough to try and take one of Yoochun's pellets. He would be overrun with the sheer amount of ki. His body would be unable to handle it. In turn, it would explode at any point of combat contact. At best crippling the child for life. At worst it would kill him.

It was a lesson in humility to see the difference between master and student. As he grew he too would get different dosages in ki pellets. It would take time and getting impatient would only hurt his progress.

Yoochun said, "You're progressing nicely," Izuku popped the pellet into his mouth grimacing slightly at the taste, "We still need to work on the amount of time it takes for you to purify your reserves. Lightning fang as you call it will only aid you so far."

Izuku replied raising his head to meet his master's piercing stare, "Yes Sensei."

The moment the words left his mouth the air became charged. It was a thousand times more powerful than when he was calling forth his elemental ki.

Despite himself, Izuku couldn't stop himself from stepping back. Lightning encased both of the man's arms. Something feral had entered the man's eyes.

Yoochun began as lightning jumped from hand to hand until it created a constant stream of lightning, "I call this ability Electric Yo-yo," Izuku was cut off as he opened his mouth, "Yes brat like the toy. When you get to the point where you are constantly purifying your ki then you can use this technique."

Yoochun paused allowing the boy to analyze the technique first hand. It was a medium to long-range attack. Its upsides were to prevent an enemy from getting close. The downsides were the amount of ki needed to use it.

In his current state, Izuku could only hold that technique for maybe a second. Before his reserves were depleted.

Then as quickly as it had come the feral presence was gone. Yoochun's easy-going attitude had returned as the lightning faded.

Yoochun continued as he took a deep breath, "There is one other major technique in the Enlightenment of Thunder and Lightning. My master only spoke of it in theory but it's supposed to be the most powerful to date. As far as I know, it doesn't even have an official name. This is most likely due to the fact no one in recent memory has successfully performed it. It's also the most dangerous technique I have. So much so that I can't even show you for I have never been forced to use it myself. I will give you a theory so that you have it in case the day ever comes that you need it."

So powerful even his master couldn't use it? What was this technique?

For the briefest moment, a far off look entered his master's eyes. It was so pained that Izuku wanted to help. He wanted to take away the pain but he didn't know-how.

Then he continued, "At your stage, you wouldn't be very effective when using this technique. The amount of unpurified ki you're able to hold is minimal. Purified ki is even smaller. This is okay because you're just beginning your training. The more we practice the stronger you will get. When you have a significant amount of unpurified ki. This is extremely important. It must be unpurified to use this technique. You will grip it as if you're purifying it the normal way before training. Instead of just getting a small amount of ki that you can filter. You WILL get all of and purify it all at once."

Izuku stepped back instinctively in shock. When he first began his training Yoochun had warned him about taking too much ki to purify at one time. On the first day, he had to use Thunder Break to discharge the extra build-up of ki five times before Izuku finally got purifying down.

Thunder Break was a technique used to disrupt the natural flow of electronics. It could also be used to unstun someone hit with Lightning Fang. This would prevent excess damage to someone in the event of a fight. Or in Izuku's case trying to purify too much ki at one time.

Yoochun sighed, "Its a move of last resort. That is why I have never used it. My predecessor only used it once himself and that was before I joined as a disciple. In theory, it would work against villains whose bodies are liquid. Or against those who specialize in water-based attacks. As I said though it is a move of last resort. If you use it against a person or near a person uses Thunder Break to keep their hearts beating and out of a coma. Using it too often can damage your ki center. So be very careful about when you choose to use it."

Izuku nodded. If he was to use this technique it would be a last resort. He was determined to get stronger so that he would never have to.

End of flashback

Izuku's body was moving before he realized it. Behind him, heroes and civilians alike called out trying to stop him.

The green blob of a villain tried to attack him. He dodged by planting his left foot and turned to his left. A duck later and the claw-like attack missed him by several inches.

Izuku lunged using his ki to launch himself at the villain. His shoulder connected but it was as if he hit a brick wall. With that, he retreated two steps then lunged again.

He snarled, "Kaachan clench your teeth."

That was the only warning he gave before he pulled at his ki. Gathering it all he pushed it through filtering it all at once. Lightning coursed over his body then it exploded outwards.

The ki coursed over the liquid body causing Kaachan to let out a muffled cry. The liquid body dropped him unable to keep the boy any longer.

Izuku's hand went to where his ki pellets lay. He snapped one into his palm then bit into it. The rush of ki flooding back into him no longer made him stagger.

Dropping to his knees before Kaachan he placed his hand on the other's chest. Forcing his ki to purify in a small amount he focused it into a negatively charged state to cancel out the positively charged attack.

The moment his attack was canceled out on Kaachan the boy jackknifed up. His breathing ragged with wild red eyes. A pissed off look crossed his face. No doubt he was pissed that Izuku had saved him.

Both boys looked up as the green villain launched at them. A flash of bright yellow launched itself at the villain.

A voice yelled, "There's no need to fear. For I AM HERE!"

All Might! Both boys watched in stunned silence as All Might used Detriot Smash to stop the villain.

When it was bottled up to keep the villain from escaping. Izuku got chewed out by the pro heroes who were originally onscene. Kaachan got praised for his bravery.

Once they were checked out by medics they were cleared to leave. The only thing that was wrong with Izuku was that he had mild exhaustion. His training plus using a last resort technique cost him greatly. The exhaustion ate at him as he made his way home.

Kaachan was uncharacteristically quiet by his side. It wasnt until they were at the corner of his house did he speak up. When he did it was in the usual angry fashion.

Bakugo snapped angrily, "What the hell did you do that for, Deku? Why would a quirkless bastard like yourself risk everything for me?"

Izuku sighed silently as he came to a stop. Turning back to his childhood friend he answered truthfully, "My body moved on its own. Even if it didnt I wouldn't have stood by while someone was getting hurt. Not while I could do something about it. Even going so far as to risk my own body and life. That is what it means to be a hero, Kaachan."

Bakugo growled as he turned towards his house, "Idiot. I didnt need your help. Don't do it again, Deku."

With that, he was gone leaving Izuku on his own in the street. The younger boy let out another sigh. Regardless of whether or not he actually wanted to fight he would. Chun told him that you couldn't know if you were going to win or lose unless you gave it you're all. Winning or losing meant nothing. Only giving it your all and putting everything you had into the battle.

Izuku then turned back towards where his own house was. There was little else he could do today. Pushing his body any harder would only be detrimental to his training. Sleep was the best thing for him now.

He was started when a blond-haired man with bright blue eyes turned around the corner. The man had hallowed eyes and cheeks but the life in his eyes betrayed that. They became even brighter at the sight of him.

Izuku queried, "What can I do for you, mister?"

The man blinked then replied, "Ah I'm sorry. I forget that people don't know what I look like normally."

There was an influx of power that made the hairs on the back of his neck rise. Subtly he slipped his right foot back readying his stance. If this man attacked him he might be in trouble.

Then suddenly the man bulked up and became All Might. The sheer power behind the man told him this was no imposter. Sight could be fooled but ki could not be fooled.

"All Might," he breathed, "What are you doing here?"

All Might said, "Your actions earlier inspired me," he coughed up blood and with a puff of smoke was back to the previous form, "You see I can only hold my All Might form for so long every day. When your friend was attacked I was already at my limit. Seeing you risk everything for young Bakugo inspired me to jump back into action. I forced myself to push past my limits into the form. His shock at being attacked by the lighting attack of yours allowed us to capture him without issue."

Here the man paused to take a breath. He seemed to consider everything about Izuku before he continued, "After that, I asked around about you. I found out that despite being born quirkless you have strived to master martial arts. That you want to be the first quirkless hero."

This was it. All Might was going to shoot down his dreams like everyone else.

Izuku could ignore other's shooting him down. What they meant very little to him. All Might was his childhood hero. What the man thought meant the world to him. It would hurt more than any wound if his hero denied his dream.

"If you had asked me before this if I thought you had a chance at being a hero. I would have told you no but seeing your spirit today. I know that you can be a hero," finished All Might.

Izuku could only stare dumbly at the man. What? What did he mean? What could All Might do that he wasnt already trying?

The man lifted his shirt showing a mortal wound. It looked worse than anything he had seen before. There were quite a few terrible-looking wounds he had seen on his own master.

Yoochun was reckless in his fights. He would give everything he had and held nothing back. There were times when Izuku would wonder how he made it to his early thirties at all.

The man said tiredly, "I came back to town hoping to find a successor. As it stands now I can barely do any pro hero work. I hoped to find my successor at UA. Instead I found what I was looking for in the most unlikely of places."

"A successor?"

All Might nodded and continued, "You see my quirk is different from everyone else's. One for all is not passed from parent to child. But chosen successor by the current user. I can give you a quirk and train you to be the next Symbol of Peace."

This was all he ever wanted. To have a quirk and to become a pro hero. As a feeling unfamiliar to him filled his chest regret also chose to rise. He couldn't just outright agree. He was the disciple of Chun. There were still training he had to do with the man.

Quietly but firmly he said, "I want nothing more than to agree to this. But I am a disciple in Murim. We will have to work around the training with my master."

All Might grinned as he finished, "I can work around that. You have a strong ethic. It seems I chose right for my successor."