Keychain | Death Note | Embroidered (see variants)

Death Note (from Fandom Death Note Wiki)
High school student Light Yagami discovers a supernatural notebook that allows him to kill anyone by writing the victim's name while picturing their face. The story follows his attempts to become a god by creating a New World cleansed of evil by using the notebook, and the complex conflict between himself and all those who try to stop or help him.