Blood Daughter manifests as a tall woman clad in black, possessing long, dark hair. Her face remains concealed beneath a distinctive grey, claw-like mask featuring an inhuman bird-like beak. Twig-like textures mark parts of her form. Her signature ability, Internal Rupturing, enables her to transform into black smoke and infiltrate targets through wounds created by her partner, Veronica Thorn, destroying them from within. Though capable in physical combat, this internal assault represents her most formidable power.

Initially, Blood Daughter serves solely as Veronica Thorn's weapon for vengeance within antagonistic groups. Their partnership undergoes a pivotal shift when Veronica suffers a mortal wound. In her final moments, Veronica willingly merges her essence with Blood Daughter. This sacrifice leads Blood Daughter to subsequently bond with Marlya Noel. This union creates a new, combined fairy entity, integrating Blood Daughter with Marlya's existing fairy, Ash Clad. This merged form plays a crucial role in the final confrontation against a divine beast, signifying Blood Daughter's transition from a tool of destruction into a component of a protective force. This integration indirectly fulfills Veronica Thorn's lingering influence through Marlya Noel.