Guinevere appears in the narrative as a figure tied to the secret organization known as Idea. Her background suggests she is not merely an ordinary human but rather the legendary Guinevere of Arthurian myth, having survived through the centuries. As a member of Idea, her primary motivation is the preservation of the historical record, a mission she pursues with a firm and unwavering conviction. Her role in the story is largely defined by her allegiance to this cause, which places her in direct opposition to the protagonist, Cardia. Specifically, she becomes convinced that Cardia must be eliminated for the greater good of history, positioning her as an adversarial force driven by ideological rather than personal reasons. Her key relationship is with Saint, another member of Idea, with whom she discusses her views on Cardia.

No information is available regarding her personality beyond her stated convictions, her specific motivations beyond her duty to preserve history, her development throughout the story, or any notable abilities she may possess.