Gyōsei is one of the three governing rulers of the Underworld, holding the specific title of Executive alongside the Legislator and Justice. This position grants him significant administrative authority over underworld affairs. In his human guise, he presents with light-colored hair slicked back, adorned in traditional Chinese attire resembling a Jao Kan gown layered over a black shirt, pants, and gloves. His true form manifests as a massive black crow, emitting a suffocating aura capable of overwhelming nearby humans, as demonstrated when Hanae Ashiya struggled to breathe in his presence. His abilities include voluntary transformation between forms, aura-based suffocation, and touch-induced paralysis, which he employs ruthlessly against humans.

Gyōsei harbors a profound disdain for humans, viewing them as threats to the Underworld's stability, with particular animosity directed at Hanae Ashiya. However, he demonstrates a notable exception in his relationship with Haruitsuki Abeno, whom he tutored during Abeno's childhood, instructing him on underworld lore and customs. This mentorship arose from Gyōsei's recognition of Abeno's exceptional learning aptitude and meticulous nature, though it did not diminish his overall contempt for humanity. Characterized by isolationism, Gyōsei frequently declines social invitations, citing preoccupation with work, leading others like Shihō to perceive him as a shut-in. As a governing figure, his interactions occur primarily with the other two underworld rulers and Abeno, with his authority occasionally intersecting with the operations of the Mononokean regarding policies affecting human-yōkai interactions.