Based on the provided sources, the character Buiyosen is identified by name and voice actor attribution. Specific details regarding background, role, character development, or narrative involvement across any seasons, films, OVAs, or spin-offs remain undisclosed. Buiyosen is listed as a new cast member for the anime's second season. One promotional video highlights a battle scenario labeled "Rōjī vs. Buiyosen," but this reference does not elaborate on the character's traits, origins, or significance within the story.