Nine year old Midoriya Izuku disappeared after getting caught in the middle of crossfire between an unknown Villain and a new Hero. The police looked for the missing kid for an entire week, but to no avail, Izuku was gone and had left no trail behind. Until he appeared on his bed one night, as if nothing had happened, with no memory of the time he was lost... or atleast that is what people were left to believe because Izuku remembers everything. He remembers being a toddler again, freezing alone in the winter in the middle of a snowy mountain. He remembers the couple who found him, gave one look at the scared child lost in the snowy mountain far from the nearest village and immediately took him in only so he could have a warm place to sleep until his "real" parents found him. They named him Kioshi since his memories of his origins is disoriented and gave him a family even though he just met them the day before. He remembers found them murdered inside their own house leaving his oldest sister as the only survivor. He remember avenging their death together with his oldest brother while searching a cure for his sister. He remember dying to protected his older brother with his own body from their family murderer. Or Izuku was sent to the past, became a Demon Slayer, and now spends his days being an vigilante who too smart for his own good. Thank god Aizawa has migraine medicine and a heart full of patience for Problem Child (1) No beta we die like Izuku