Seichii Yamashiro is a character in the Devil Summoner series.
Shin Megami Tensei: Devil Summoner
Yamashiro works alongside Sid Davis to capture Kumiko Hatano, who would be a vessel for Inaruna. When confronted by the protagonist in the senate chamber, Sid escapes into the Fake Astral Plane with Kumiko and Yamashiro reveals his true form as the Demiurge and attempts to kill him. However, the Demiurge is defeated and Rei Reiho teleports the protagonist to the Fake Astral Plane using the same magic circle that Sid used.