Endless Adventure

I looked at all the water tanks and saw many familiar faces, they were all the previous One for All users. I feigned ignorance and said, "You are trapped you can't escape me!"

All for One sneered and said, "I don't have to! As I'm capable of leaving this place without even a scratch!"

"What makes you so sure you can?" I asked.

"You're gonna die so ill enlighten you!" As he said that I knew what was happening. This is it that ultimate villain exposition aka evil plan monologue.

All for One looked at Kurogiri and Tomura and made them sleep. After that he looked at me and said, "Let me explain what All Might's Quirk is. It is called "One for All" and it was once the Quirk of my brother who you can see in the tank. It can stack up power and pass it to other people. It is a Quirk with a lot of potential. My Quirk is called "All for One" and I can give others and steal Quirks. The only Quirk I could never steal is "One for All" my greatest nemesis. As the Quirk could only be passed down if the current wielder wants it is almost impossible to steal the Quirk." He stopped there and looked at water tanks.

After that he again looked at me and said, "But what if I used my mind control ability to make the current user give it to me? Sadly I understood it too late as the second user of the One for All had total immunity towards mind control. And it was passed to every later generations. I couldn't steal One for All no matter what I tried!" After that he went to the nearest water tank and looked at the person inside of it. He was All for One's brother and first User of One for All.

He then looked at me again and said, "I couldn't steal it in later generations but what if I stole it using the predecessors? I saved my brother in this water tank for hundreds of years. The water in the tank is mixed with my blood so it can make other people live longer. But if they leave the tank they would all die off instantly. Their minds could still function. It was because of the familial ties but now I have a clear goal. My goal was to connect every consciousness of One for All users and make them influence the current user to give the power to me. The consciousness of every generation is connected meaning that I could influence the current user by controlling the weak minded pass generation users. I could connect my brothers mind to the second user. Even thought second user has immunity to mind control it would be useless as my brother would create an opening for me." He said but then stopped. He became angry.

He said, "But till now I couldn't fully control the One for All users. That's because as the power is passed down the connection between past and current users get thinner. Third user of One for All could easily use power of the second user. But the last user of One for All, All Might, could not use any power of the past users. Because of the thin connection that connected them. But a year ago I had a breakthrough. After I got the lucky Quirk I had a breakthrough. All for One who was injured was totally healed. Not only that his potential was unlocked and he could finally use the Quirk of the past One for All users. This made the connection stronger giving me a chance to influence All Mights mind. It wasn't perfect but still it was an opening. After that something more amazing happened I found an ideal person who would help me!" After that he looked towards the door and I saw a Gigantomachia entering he was carrying an unconscious boy with a green hair.

All for One looked at him and said, "This boys ability is amazing. Strongest I've ever seen! Even stronger than yours! Your greatest mistake was to not kill this boy! From what I observed his ability was Biokinesis and he could one day learn an ability called "Generic Memory". The user is able to access memories and information stored in their genetic code. In most cases, this results in the user calling upon their ancestors or relatives. And in our case he could perfectly connect to past One for All users. Perfectly inheriting their power and making him most vulnerable to the control. I couldn't fully control All Might but I could still make him pass his powers to this boy. And after that I would use his ability to fully connect with the past One for All users. Then control him to give me all the powers!"

All For One transformed his fingers into jagged, far-reaching spikes and pierced Izuku. It was his ability called "Forced Quirk Activation".