A Black Disciple who together with his brother Lhusim led a army of the dead into the Realm of Ulgu seeking the Shadow Queen Morathi who had offended their master Nagash by stealing souls of slain Aelves from the imprisoned Chaos god Slaanesh. They entered the Umbral Veil where they were challenged by her and her Daughters of Khaine and in the ensuing battle all but Lhusim were slain.
A black-cloaked figure who wears a mask of silver and carries a skull-tipped staff, he is small and slight in statue, almost childlike. They sit upon thrones shaped from twisted ogor rib cages in a palanquin stitched together from corpses and enclosed by curtains of stitched hide. 
|What glory the Lord Arkhan will lavish upon us when our task is done, what profane secrets he might reveal. You and I, Lhusim, first amongst his Black Disciples, as is only right and proper.
~ Rhedgar to Lhusim.