Named by his brother Rhedgar as First of the Black Disciples the two of them 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 and he was taken for further interrogation by the enraged Morathi.
A black-cloaked figure who wears a mask of silver and carries a skull-tipped staff. he and his brother sit upon thrones shaped from twisted ogor ribcages in a palanquin stitched together from corpses and enclosed by curtains of stitched hide. 
|You will see. Oh yes, you will see. The barrow-kingdoms are emptied, and unquiet spirits rise in every corner of the underworlds. The skies above the Black Citadel blaze with amethyst fire, and the great work approaches completion. An end is coming, witch-kin. Death will have its due.
~ Lhusim to Morathi.