Miglieglia is a young girl possessing gray hair and golden yellow eyes. Her origins lie in artificial creation through experiments by Elaine Bluelake, the researcher who developed the Incarnate soldiers. Miglieglia developed as a fetus within Elaine's corpse after Elaine's death, discovered by Cain Madhouse during his examination of the body in the laboratory. This unique origin made her an Incarnate from birth without an incarnate core. Cain named her Miglieglia Cochlea and raised her after identifying her nature.

Her abilities center on necromancy, enabling her to reanimate corpses into zombies by spreading a special powder, a power fitting her designation as a Lich Incarnate. Throughout the story, Miglieglia frequently accompanies Cain, acting as his subordinate and companion. She observes his interactions in locations like Whitechurch, where they confront characters such as Hank Henriette and Schaal. On one occasion, she delivers Cain's invitation to Hank by dropping a letter specifying a meeting location. Her presence consistently supports Cain's broader objectives, including his conflicts with former allies.

Miglieglia's background ties closely to key figures: Elaine as her deceased mother and Cain as her guardian. Her existence stems from Elaine's attempts to prevent further incarnate research, indirectly causing Miglieglia's posthumous birth. Cain's role in her upbringing shapes her allegiance to him, positioning her as an antagonist aligned with his faction, the Free Nation of New Patria.