How all Dagoth Ur wanted was to chase the Imperial invaders from Morrowind and get justice for Nerevar’s death. How the negative effects of the Corprus were an accident, Dagoth Ur was trying to make something positive but completely messed up, he never intended for the Corprus as it is to be released. They learned how it was the Tribunal who betrayed Nerevar and turned his living corpse against Dagoth Ur so they could get the tools and obtain godhood. They learned that much of what they had learned was actually just misleading propaganda spread by the Empire and the Temple to try to keep the truth about The Sixth House and just what happened at Red Mountain from getting out. their corprus was too advanced so the went directly to Dagoth Ur. By the time they broke out of their trance and remembered to go to Divayth Fyr, it was too late. Zigus was Nerevarine, but once they got Corprus from Dagoth Gares, they felt called to Red Mountain.