Some Energy, please

A young man is voluntarily sent to a parallel world. However, not everything is going as planned, reappearing in the body of a person who has just been slit's throated isn't good news.\nMoreover, after crossing the dimensions, his soul got some demons clung to it, wanting to steal the body that the boy was going to take. But even for demons, not everything is simple. Only one demon survives the crossing...