One of the most formidable onmyouji of Abe no Seimei's time, Ashiya Douman was basically Seimei's rival back when they were both active nearly a thousand years ago. The two clashed repeatedly, establishing a legendary feud that apparently still matters somehow.
In more recent events, Douman's shown a real interest in Yakou's reincarnation—enough that it seems connected to his involvement with the Twin Horn Syndicate, also called the Bicornis Fellowship. He's also tied to Kakugyouki in ways that aren't entirely clear, but the connections keep popping up.
He's also the reason Jin Ohtomo lost his leg. That fight between them left a permanent mark, literally.
Content compiled by AnimeList.moe from publicly available sources.
