Armelina

Armelina is the demon who brings the main character back to life in the body of highschool student Gamou Shouya. The oringinal Shouya offered Armelina his body on his death bed in exchange of curing his younger sister from a rare illness. Now with the main character in Shouya's body he becomes Armelina's hitman to kill evil people and offering their souls to her. In return he gets the chance to take revenge on the ones who murdered him and his family.