Following defeat by the hero Max and a ten-year slumber, the character resurrects prematurely, severely weakened, resulting in a youthful, androgynous body. This form possesses light blue hair, rose-colored eyes (including a distinctive third eye on the forehead), pointed ears, and red devil horns. To navigate the modernized society developed during the absence, this form can transform into an attractive school-aged girl, often wearing a female school uniform. Masculine pronouns are consistently used despite this feminine presentation, reflecting inherent gender fluidity; the character questions whether gender truly matters when appearance is challenged.

Driven by a desire for a worthy rematch, the character seeks Max, only to find the former hero a disillusioned, unemployed recluse living in squalor. Disappointed yet recognizing Max's underlying potential, the character moves into Max's apartment. The initial goal involves rehabilitating Max back into heroic shape through domestic support like cooking, cleaning, and moral encouragement, while waiting for personal power to regenerate sufficiently for their eventual confrontation. This living arrangement evolves beyond rivalry as genuine concern develops for Max's well-being and disillusionment with the world that discarded him.

Despite maintaining villainous proclamations about world domination and being a Card-Carrying Villain, actions reveal a fundamentally benevolent and respectful nature. Historical leadership of the demon army included providing generous benefits like sick days and fair pay to subordinates. The character demonstrates unwavering admiration for Max and his former party members as Worthy Opponents, historically offering them alliances to rule together. This respect persists after finding Max at his lowest point, transforming into active efforts to improve his life. Loyalty extends to fiercely protective subordinates like the secretary Zenia, who relocates nearby to monitor the situation.

The dynamic with Max deepens significantly over time, evolving from adversarial intentions to a complex partnership marked by domesticity and mutual dependence. Co-habitation involves performing household chores and offering emotional support, leading others to frequently mistake them for a couple. Persistent efforts include invitations for Max to become an immortal demon to ensure their partnership lasts forever. This relationship progresses to marriage, culminating in a future depicted in bonus material showing the character walking hand-in-hand with their young son, indicating a conventional family outcome.

Involvement extends beyond Max's personal rehabilitation into broader conflicts involving his former adventuring party. The character becomes entangled in political tensions between the Kingdom's Magic Bureau, led by the cleric Fred, and the Gamma Republic, founded by the warrior Leo. These conflicts stem from the kingdom's abandonment of heroes and exploitation of resources. Using retained abilities like flight and potent magic, despite being weakened, the character intervenes in situations such as suppressing Leo's magical attacks or gathering intelligence, often driven by a desire to aid Max or protect their shared living situation. The narrative explores themes of purpose and societal rejection through these engagements.

A notable shift occurs when the character achieves full resurrection later in the story, seemingly with assistance from another demon (Astaroth). This restoration includes a complete transition into a physically female form. The permanence of this change remains ambiguous, though it aligns with the character's established gender fluidity and earlier transformations. This development coincides with the deepening bond with Max, ultimately leading to their marriage and family life.