Who is Tomas from Silverthorn and what is their importance?

The elven queen's husband, Tomas, is part human and part Valheru. He is unable to assist Arutha in his search for the Silverthorn because it is his responsibility to stay with the child. He can, however, protect his domain, and when the Black Slayers crossed into elven territory, Tomas used Valheru magic to kill and destroy them.