Finally it was time for a showdown with Tartarus at the top of the structure. His go to combo was hiding in his god shield and summoning a miniature black hole that tracks and insta kills. Fortunately, it can be used against him through either Fus Ro Dah or simply being fast - which I was thanks to the night sky and shadow armor. The black hole would destroy his shield and leave him open for attacks.
Of course this is in between him summoning drop ships of "elites" and skeletons who can't be hurt and to be frank - was getting really annoying. Especially since I must have crashed around 100 times playing through this mod just to reach here. Since my PC couldn't really take any more I simply broke the script and during one of his "I can take damage but if I take enough I'll turn on the god shield again" I pulled out my strongest weapons and eviscerated the asshole before he could jump back behind his protection.
That's what you get for summoning the shield then trying to run to it.
With this job done I then used the asylum teleport to get myself the heck out of there and back to Bo and Sofia. In my absence they had gone ahead and tracked down that missing Vigilant caravan. They brought proof it had been attacked by necromancers, and had a lead on where to find them.