I suspect you might be a bit character heavy? I’d lose a couple and lean into the summonable side. Add in some black knights. Maybe a unit of blood knights? More hammers and more bodies needed so you can out attrition the opposition in the late game?
I agree that he is way too expensive, especially since he can no longer spam Arcane Bolts. However, two 30's of skeletons aren't going anywhere with him around. 5+ ward, combat phase regen, Nagash regen and SBGL regen on your turns. It's pretty beefy. I have played a list of two 30s of skeletons (or three 20s), a unit of wolves, Nagash, Cogs (mandatory), and two vampire lords in Vrykos to get the extra unit of wolves and keep them healthy. (Get the 5+ ward artifact so you can spread out from Nagash.) You would have enough points to get another endless spell as well. (Life-swarm) You could One-Drop or go for a Command Entourage. It has worked pretty well, but no one I play with goes crazy with shooting, which is still Nagash's big weakness. It's pretty much just parking on 3 objectives and scoring points, while Nagash strategically excises things from the board when the opportunities present themselves, but it has gotten the job done pretty consistently. Probably not tournament level though.
