Sesshoumaru or as Amia and I call him, Fluffy or Sesshy, is the older half brother of Inu-Yasha in the anime called Inu-Yasha. He wonders a lot around with a young human girl, Rin and a frog demon, uhm.. I don't know, following behind him. Oh and he hates his brother.
In Elyasia, Sesshoumaru has known about this world and has been seen walking around without Rin or that frog demon. Lyra has meet with the demon lord. Same as Mira, but she didn't tell him about his son. Anyways. Sesshoumaru is the father of Mathias. He's mate is at this time, unknown to the world of Elyasia.