Shin emerges as the central antagonist in the series' second season, a formidable Yuragi demon who commands immense power. Defying the solitary nature of his kind, he unites Tokyo's street-infesting Yuragi under his leadership, driven by primal instincts toward a shared objective. This unprecedented unity amplifies their threat beyond previous demon activities.

His past intertwines with Rin, a magical warrior opposing the Yuragi, through an act of violation that resulted in their daughter Mayu's birth. Shin now exploits Mayu's existence to advance his scheme: creating a Yuragi-exclusive "paradise," leveraging her as a crucial component of his dark vision.

Characterized by near-overpowering strength, Shin presents an extreme challenge to protagonists Ai, Rin, and Meg. The conflict centers on thwarting his unified demon forces and preventing his establishment of a demonic stronghold. His actions directly ignite the season's escalating central conflict, positioning him as the primary catalyst driving the narrative.