The tomb of kings, a place so far beneath the ground which housed all the greatest kings of phlyndir, now home to the graveking Sif. Sif was the first person to experience death without truly dying but was sealed in a stone coffin due to the unnerving ability of not dying. He was later on uncovered by Faust who he granted the ability of undeath to along with his entire circle of researchers who had now become his necromancers. Sif cursed the entire city of Astora to eternal undeath and now rules over an army of the undead.
When facing sif, one has the option to fight him and kill him ensuring that no more can be affected by the curse of undeath or join him as his servant and become one of the few undead allowed to roam outside of the walls of Astora as long as you claim the eyes of those who live and pay tribute to Sif with these. With enough tributes Sif will award his servants with disease causing weapons and items.