Power

Blood Fiend. As a fiend, she possessed relatively high intelligence and rationality, which led to her being taken under Makima's protection and becoming a Devil Hunter in the Public Safety Devil Hunters' Special Division 4 despite being a fiend. She appears as a young woman in her late teens, with long flaxen hair, two horns on the top of her head, and irises with a cross pattern. She refers to herself as "Washi" and speaks in an old-fashioned manner, but in reality, she is childish, extremely self-centered, and selfish. She often contradicts herself, has a tendency to lie, and is irresponsible, often shifting blame for unfavorable situations. Due to her origins as a devil, she is prideful and arrogant but tends to prioritize self-preservation and not oppose those stronger than herself.

She has the ability to manipulate blood, allowing her to solidify it to create weapons or control her own or others' blood to stop bleeding. However, she mentions that she struggles with manipulating others' blood due to being in a fiend state. She can enhance her power by consuming blood, but conversely, if she uses too much blood, she becomes anemic and unable to move.

She becomes Denji's partner upon his joining of Special Division 4, initially distrusting humans, but builds a bond of trust with him after he saves her beloved cat, "Meowy." After partnering with Denji, she lives with him at Aki's residence and participates in various missions, but is later killed by Makima, who harbors her own secret motives. However, because she had previously allowed Denji to consume her blood, she barely survives within Denji and is resurrected in her original form as the Blood Devil. Despite sustaining fatal injuries, she protects Denji from Makima and, in her final moments, makes a contract to give Denji her blood in exchange for him finding the Blood Devil and becoming friends again someday, reviving Denji before disappearing.

In Chapter 83, she is counted among Makima's followers of Chainsaw Man.

Blood Devil

Power's original form as a devil. She has a carnivorous beast-like appearance with a feminine physique, characterized by four arms and exposed organs from her jaw to her abdomen. She retains features similar to her fiend form, such as cross-shaped eyes, hair, and horns. Her ability to manipulate blood is significantly more powerful than in her fiend form, allowing her to create weapons from others' blood to cut from within their bodies or generate and launch a large number of weapons in the air. Her personality remains unchanged.