Izuku was protecting Eri from Overhaul who escaped from prison, in desperation he creates a portal that sends them to a world of demons and Demon hunters.
This is a sequel to Kuro Izuku since I had the idea for a while.
Izuku and Eri were wandering through a village in the western side of Tokyo, Izuku had informed U.A. and his mother about where he and Eri were, and he was given a small wireless camera and mic to wear on his clothing. He then goes up Mt. Kumotori.
Eri: I hope we meet some nice people Papa.
Izuku: Me too Eri.
They continued up until they saw a boy on the ground holding a hatchet with a girl biting down on it then they saw that the girl was actually a demon.
???: Nezuko please, control yourself.
The girl now known as Nezuko started crying.
Izuku (mind): She must be his younger sister.
Danger sense then goes off.
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He then sees a young black-haired swordsman restraining the girl with the sword at her neck.
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Eri: We got to help them, Papa.
Izuku: I know Eri, but I feel like that boy is more skilled than he seems.
They watch the battle go the same as canon up until the hatchet hits the tree.
Eri: How'd he do that Papa?
Izuku: Easy Eri, he threw the rock as a distraction, then when he was behind the tree he threw the hatchet, he kept his arms hidden to make it look like he still had the hatchet. My guess is he was planning to take him down before the swordsman knocked him unconscious, but he did it too early and he noticed it right away.
They then see the girl break out of the boy's grip and run to her brother, but instead of attacking him, she is protecting him.
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