Nathan Mahler is a chiropteran who serves as one of Diva's chevaliers, though the precise circumstances of his origin remain ambiguous within the anime. He is among the oldest of Diva's attendants, yet the true nature of his bond with her is left unclear. In his human identity, Nathan assumes the role of director of the Metropolitan Opera in New York, a position he uses to promote Diva and her singing on a global stage. He first appears in episode twenty of the series and quickly establishes himself as the most outwardly colorful and flamboyant member of the group known as Cinq Flèches, the five chevaliers who serve Diva. Unlike the more dour or ruthless personalities of his fellow chevaliers, Nathan carries himself with a lighthearted, sometimes frivolous demeanor that contrasts sharply with the violence around him. He provides a degree of comic relief within the otherwise grim organization, often through his interactions with James Ironside. Beneath this theatrical exterior, however, Nathan is capable of being calculated and ruthless when the situation demands it. He possesses a sharp intelligence and a pragmatic approach to conflict, choosing his battles carefully and often refraining from direct aggression. Nathan is notably one of the two chevaliers who does not wish for Saya's death, preferring a more neutral stance in the long war between the twin queens. His primary motivation centers on Diva's happiness, and he appears to genuinely support her dreams and desires as much as possible, even when those dreams conflict with the interests of his fellow chevaliers. He values her well-being above the broader schemes of Amshel Goldsmith, the de facto leader of the group. In terms of relationships, Nathan maintains a distinct distance from the others, especially from Amshel, whose manipulative and destructive plans he does not fully endorse. He shows a measure of tolerance and even occasional kindness toward Solomon Goldsmith, even releasing him at a critical moment when Solomon is weakened. His bond with Diva is the central axis of his character, and he behaves as a devoted guardian of her vision rather than a servant of the organization's larger agenda. Throughout the story, Nathan's role evolves from a seemingly eccentric supporting figure to one who quietly opposes the more extreme actions of his peers. He demonstrates notable abilities befitting a chevalier, including enhanced strength, speed, and regenerative capabilities. In his chiropteran form, he grows taller, reaching roughly six feet three inches, and his physical power increases substantially. His human form stands around five feet eleven inches, with blonde hair and blue eyes that contribute to his distinctive appearance. Despite his death at Saya's hands late in the series, his fate carries a degree of ambiguity, as he is glimpsed afterward in the guise of a reporter, suggesting he may have survived or that his presence lingers in some form. In the light novels, an alternative backstory is provided: the original Nathan Mahler was killed by a surviving chevalier of Saya and Diva's mother, and that chevalier then took on Nathan's identity and place among Diva's attendants. This layered history reinforces the sense of mystery that surrounds his character throughout the anime.