Are you worthy enough? Mha x Male!Reader

What happens when a demon king on death row ends up in a human relm? A human relm with humans that have powers. Its sure to be quite enjoyable, right...? No. KnY, Mha nor the characters do not belong to me! They belong to the creators. (Nothing but the story idea belongs to me!) Mha belongs to Kōhei Horikoshi. KnY...