Izuku smiled at the supervillain.

  "What do you want to talk about?" He asked.

  All for One chuckled quietly.

  "Well, I have watched your career with interest. The analysis you have done on heroes and villains alike is most impressive. I would like to.. request that you join me. I have many uses for the knowledge you carry." He said.

  Izuku hummed in thought.

  "And if I refuse?" He asked.

  "Most unfortunate..."

  All for One surged forwards at an impossible speed.

  "I shall have to make you."

  The villain reached out and placed his hand over Izuku's face.

____________________

  All Might stood in a room full of heroes. Most of the top ten were here, and several skilled heroes were also present. Nezu was the one leading the raids.

  "Best Jeanist, take a few heroes and target the Nomu factory. The beacon Yayorozu was able to make will lead you there. They won't fight back without orders, do you shouldn't worry about disposing of them, just move them from where they're supposed to be. That will prevent the warper from collecting reinforcements."

  The number three hero nodded, gazing down at the maps plans and files strewn across the large table.

  "All Might, you take the lead on the bar raid. That is most likely where they're holding Midoriya. The leader will probably be there too."

  All Might got the unspoken message.

  You take All for One down for good this time. If you take him out of the picture, the league will quickly fall too.

_______________

  Izuku blinked. Interesting. He was in a very long, very tall corridor. The walls were bookshelves that stretched up until he couldn't see them anymore, and across until they disappeared into the distance. The bookshelves were full of notebooks. Hundreds of thousands of notebooks, all different sizes, thicknesses, colours and formats.

  Some were ratty old ones, others were shiny and new. A few were old and well worn, but obviously well looked after.

  Izuku selected an older notebook, opening it.

  He blinked.

  He was.. in a familiar place. The doctors office.

  "Sorry kid, but it's not happening."

  Izuku's eyes widened.

  "Interesting. So the notebooks are.. memories? So this is my mindscape."

  Izuku was still holding the notebook. He closed it, and he went back to the notebook corridor.

  Izuku turned around, spotting a large wooden door, hanging open. There was a white room, and then another door, also open. Izuku could see a cozy living room, modeled from the pre quirk era. There was an armchair, and a fireplace.

  Izuku smiled.

  "This is a very cool quirk.."

___________

  All Might knocked on the door.

  "Kamino la pizza delivery!" He said.

__________

  Izuku explored the corridor some more. He found a door, at the opposite end of the long corridor. It was locked tight. A white haired man in a bespoke suit was trying to get it open.

  "All for One?" Izuku asked.

  The man turned, surprise flashing across his features.

  "What? How are you..?"

  Izuku ignored the man, examining the door. It was labelled Izuku.

  "So.. opening this door lets you control me? Or gives you all my knowledge?" He asked.

  All for One sighed.

  "It should, but I can't get it open. There's normally a dead light above the door, but this one is on for some reason.." the man said.

  All for One rounded on Izuku.

  "However.. if I kill you then all of this becomes mine through the link.." he said.

  Izuku dodged the Villain's grasp, breaking into a sprint back down the corridor. All for One followed close behind.

  "You can't run from me boy!" He called.

  ____________

  "No more running and hiding Shigaraki! This ends tonight! Where is Young Midoriya?" All Might asked.

  Shigaraki growled.

  "You damn heroes.. I hate you all. You hear me All Might? I HATE YOU!"

  The villain hesitated a second, clearly expecting something.

  Nothing happened.

  ___________

  Izuku narrowed his eyes in concentration as he ran down the corridor of bookshelves. Notebooks were nice, but a door would be far more useful right now..

  A few seconds later, and a door came into view in place of one of the many rows of bookshelves.

  Izuku yanked the door open and stepped through, slamming it shut behind himself. He was met by a corridor of many doors lined up beside eachother. He smiled.

  "Perfect."

____________

 
  All for One was a patient man. He'd waited a hundred years to squash One for All for good, he'd waited many years to execute his revenge on the eighth, All Might.

  But this quirkless child was starting to annoy him.

  He'd opened a door that hadn't been there before, and once the villain himself opened it a few seconds later the boy had vanished. For what seemed like hours they'd played cat and mouse through the boy's memories, thoughts and feelings.

  All for One reached the door at the end of the corridor, with 'Izuku' on it, and a light still on above it. The door that All for One had been trying to break into was open. It had been closed over, but this was definitely where the boy had escaped to.

  All for One yanked the door open and stepped through, smirking in victory for a few misguided moments.

  It was a large, barren room, with a stage at the opposite end. About ten meters away, on the stage, the green haired boy that had given All for One so much trouble was dancing behind a microphone. There was music playing from somewhere, a tune the villain vaguely recognised.

  There was a second door labelled EXIT behind the boy, with a big neon sign above it that just read 'GOTCHA'.

  The first door slammed shut behind All for One, and Izuku smirked.

  Then he started singing.

__________

  Izuku opened his eyes. All for One's body was slumped on the floor, lifeless.

  *I am the ruler of the underworld! I am feared by every hero that has ever walked the earth! I am the most feared being in the world! All Might himself trembles before me!! TURN THIS FUCKING MUSIC OFF, OR I SWEAR YOUR DEATH WILL BE EXCRUCIATING!!*

  Izuku chuckled to himself, singing along to the music in his head as he searched the hideout.

  "Never gonna give you uuup~"

  He opened the door, peering cautiously into the corridor. There wasn't a person in sight.

  "Never gonna let you dooown~"

  Izuku walked down the corridor, peeking into each room as he passed.

  Chemical lab.

  Storage room.

  Janitor cuboard.

  Nomu production room.

  Chemical testing facilities.

  Guinea pig test room.

  Bingo.

  "Never gonna ruun around and, desert you!"

  All for one screeched in rage from inside Izuku's head.

  *You dare?? You dare to cross me? I will slaughter everyone you love! I will hunt down every person you have even seen and murder them without hesitation!*

  Izuku looked around the room. There were a few glass boxes, some cages with guinea pigs in them, an operating table with a body strapped to it, and a large bin labelled 'organic matter disposal'.

  "Never gonna make you cry, never gonna say goodbye."

  Izuku opened one of the cages and chose a nice fat guinea pig, opening the door keeping All for One inside his head.

  *I AM THE DARKNESS! I AM ALL POWERFUL! I LURK IN THE SHADOWS AND HUNT AT MY WHIM! YOU CANNOT DO THIS TO MAAAAAAAAAAAAGH!!!*

"Never gonna run around and, desert you." Izuku finished with a smirk.

  The guinea pig squealed in adorable rage, wiggling it's fluffy little legs in a tiny temper tantrum.

  "Let's go home, All for Dumb. Eri's gonna love you." He grinned wolfishly.