the mc is op, he is really good with dark magic. so he get to know a young wolf beast girl, that later gets killed and he looks for the killer that killed her and take revenge. But the girl is not completly dead, her soul is lingering around him and gets to know who killed the young girl. he finds out who did, and takes out the soul of the killer out of her body and puts the wolf girl into the body of the killer.

i can't remember the name. help.