Queen Leila Eberwein, consort to the deposed King of Leuven and mother to Dirk Eberwein and Princess Lilia Eberwein, possesses a slender physique, pale skin, large breasts, long blond hair parted in the middle, and green eyes. She typically wears royal dresses, capes, tiaras, and decorative accessories, though her clothing is often torn during captivity.

Following her son Dirk's coup—achieved with demonic aid to overthrow the king—Leila is captured with her daughter. Dirk, bound by a pact demanding the extraction of Lilia's holy energy through sexual means, subjects Leila to systematic degradation, torture, and sexual corruption. This includes forced incestuous relations with Dirk, participation in orgies, and being compelled into sexual acts with Lilia. Orchestrated by Dirk and his demonic enforcer Kiriko, the relentless physical and psychological abuse induces significant mental deterioration, manifesting as episodes of insanity and a gradual erosion of her dignity and will.

As Dirk's deadline to fulfill his demonic pact approaches, Leila is forced to participate in a large-scale ritual to extract Lilia's holy energy, resulting in catastrophic loss of life across the kingdom. Despite Dirk completing the ritual to fulfill his obligation to the demon king Maou, Leila is seized by Maou as part of the agreement. Her final depicted state is one of enslavement under demonic control, removed from human society and exploited as a resource alongside Lilia.

Spin-off media further explores Leila's captivity and suffering, depicting her and Lilia undergoing continued sexual torment and conditioning within Dirk's custody.