The royal priests of the Xulous kingdoms often journeyed from their ivory cities to Lxanvon on behalf of their people, to deliver offerings and praises to their dead kings. Bertoxxulous, donning the decaying bodies of the dead Xulous nobles, appeared before these royal priests demanding obedience, reverence, and sacrifices. Bertoxxulous deceived and corrupted the minds of the royal priests and their allegiance belonged to the Lord of Death and Decay above their living kings. Amidst these firsts priests of decay, one was held above the others, Ultor Szanvon the Putrid; he led the priests of decay in the spreading their dark doctrine. Ultor, an influential priest in service to the mightiest of the Xulous nobles schemed and murdered his way into the position of chief advisor to the living Xulous King. Ultor convinced Xulous King to visit the tombs of his ancestors, and there within the presence of Bertoxxulous' full might he performed a dark ritual, sacrificing the king in the bowels of the crypt. Through the dark ritual Ultor summoned twelve spirits of previous Xulous kings and bound them to his service.
The risen undead kings rose armies of the dead from the necropolis of Lxanvon and spread across the lands ravaging all in their path, and leaving only death and destruction in their wake. Those who were not destroyed by the weapons of the undead armies were killed slowly by a deadly plague, carried by the risen kings, and spread like wildfire amidst the Xulous. Their entire race succumbed to the pestilence and the Xulous were no more. Bertoxxulous, pleased and swollen with pride by his genocidal accomplishment called his minions back to the necropolis that had served as their resting place for so many years. The risen Xulous kings gathered in the bowels of their crypts as a great mist enveloped Lxanvon.
The ancient dragons watched from afar as the mists cleared, revealing only a barren and broken landscape where the necropolis had once lied. It is said that the necropolis of Lxanvon still exists in the Plane of Disease, unchanged from when the ancient dragons witnessed its vanishing from Norrath, and that the form Bertoxxulous favors when visiting Lxanvon is a twisted visage of the long dead race he destroyed, so many ages ago.