Reina stands as a core protagonist within her team, dedicated to confronting Chaos Tellers who maliciously rewrite the predetermined destinies recorded in people's Books of Fate. She wields a unique blank Book of Fate, granting her autonomy from prewritten life scripts and the power to resist the Chaos Tellers' alterations.

In combat, Reina activates a "Bookmark of Guidance," transforming into the persona of Cinderella. Within this form, she adopts a primarily supportive role, utilizing healing abilities instead of engaging in direct offensive action—a distinct contrast to teammates who manifest aggressive characters like Robin Hood or Alice.

A recurring tension emerges from the team's mandate to enforce adherence to original story paths across various Story Zones. This enforcement role sometimes clashes with individuals resisting their predetermined fates. For instance, one episode highlights a confrontation where the designated Little Red Riding Hood expresses distress over her unavoidable, cyclical fate involving being eaten by a wolf. This scenario inherently questions the ethics of enforcing potentially traumatic destinies, though Reina's personal stance on this moral conflict remains unexplored.

Specific details regarding Reina's background origins, personal history outside team activities, character development across extended arcs, relationships, motivations, or evolution in her role beyond the initial premise are absent.