Sylphid

Sylphid is one of the Four Heavenly Kings and a master of magical research. To avoid demanding duties and social interaction, she conceals herself inside a large stuffed costume and operates under the alias of her assistant 'Belinda,' keeping her true identity hidden. Possessing exceptional magical ability and sharp logical thinking, she outwardly appears lazy and averse to trouble—yet after the protagonist Uchimura sees through her disguise, she begins applying her outstanding technical skills to support the Demon King Army's organizational reforms.