Izuku was always a cheerful child as he was living with his mother, he had a friend named Katsuki Bakugo who always protected Izuku. Izuku always was good in combat situations, but one day a man known as All for one(AFO) kidnapped Izuku and took him to his base.

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AFO: Izuku Midoriya... You are quite the specimen, I am going to make great use of your talents. *evil smirks*

AFO then subjected Izuku to various experiments and replaced his arm with a Vibranium one.

After Izuku was 10 AFO got beat by All Might, but no one knew of Izuku.

After Izuku was 14 he began his missions and became wanted in every country for murder.

Then when he was 16 he got a brand new mission.

AFO: Winter soldier, your mission is to kill All Might and his entire class at the USJ.

Izuku: Yes sir.

Izuku was then prepared for his mission.

Izuku: Time to carry out the mission...

He then stepped into Kurogiri's portal with Shigaraki and other villains.