Reincarnated As The Cursed Wild Child

Elliot is ten years old. He wakes up on a cold table in an unfamiliar laboratory, tied up, watched. He is spoken to. He is asked questions. He doesn't know who he is. He doesn't know where he is. One thing is certain: something inside him shouldn't exist. Elliot is reincarnated. He was reincarnated as a baby. But why does he seem to have missed the last ten years?