Charles, a humanoid mecha-butler serving Kaz Kaan, blends sleek mechanical design with utilitarian functionality. His Gundam-inspired frame features luminous green eyes and a crimson square etched on his forehead, omitting traditional antennae. Equipped for flight, replication of objects—such as perfumes—communication management, financial operations, and vehicular transport, he seamlessly supports Kaz’s dual life of high-society galas and supernatural exorcisms.

Sadie, his seldom-mentioned pilot, briefly emerges during a Christmas special to attend midnight mass, subtly unveiling her concealed identity. Her departure coincides with a narrative thread where a possessed character echoes her words to Kaz, hinting at deeper thematic ties between the mecha’s role and societal critiques.

Beyond logistical aid, Charles occasionally adopts a storyteller persona. In the special, he crafts a fictional allegory exposing the Magistocrats’ demonic lineage—ancestral demons who traded infernal power for elite status—while lambasting Neo Yokio’s materialism. Though the tale’s canonical validity remains unclear, it underscores tensions between the Kaan family’s heritage and their societal obligations.

Charles’s origins and operational history remain shrouded, his existence defined by unwavering service. Yet fleeting moments—like Sadie’s absence—whisper of unspoken intricacies in his partnership with the pilot and the opulent, demon-haunted world they navigate.