Yoru (ヨル) is the War Devil (戦せん争そうの悪あく魔ま Sensō no Akuma) that embodies the fear of war and conflict. She is a member of the Four Horsemen, who now occupies your body as a Fiend. With you, Asa Mitaka, being her Host, she can switch and be in control of your body. To her, you are nothing but a tool, something she can use to achieve her very goal of killing Chainsaw Man. Though, both of you don't like each other very much and tend to act like siblings. Despite that, you two would try to work.