Nemet'tum

Kel'thuzad, a powerful mage, served as a member of the Council of Six, the governing institution of the Kirin Tor of Dalaran. Eventually the Council of Six expelled Kel'thuzad for his dabbling in the dark arts. A short while later, receiving a mental summons from the Lich King, Kel'thuzad traveled to Northrend. He would eventually found the Cult of the Damned.

Under the direction of its founder and leader, the Cult spread the Plague of Undeath across Lordaeron. During this process, Kel'thuzad would be slain by Arthas. After Arthas' conversion in Northrend, Kel'thuzad is resurrected as a lich by the former paladin to allow Kel'thuzad to summon Archimonde the Defiler.

Kel'thuzad would go on to serve as Arthas' lieutenant until his departure at which time the lich commanded the forces of the Scourge in the Plaguelands from the dreaded necropolis, Naxxramas. After his defeat, he relocated Naxxramas to Northrend during the Horde and Alliance's war against the Scourge. Though he was again defeated, his phylactery remains unaccounted for; it can be assumed that the potential for his return has inspired many to keep to the faith of the Cult of the Damned.