So I posted my problem in the toughest encounters thread, and figured I should post it separate because I am stuck.

I went through a quest to find more info about Dragonborn and shouting, or something of that nature. So it took me to Valthume (tough place to find). This blue dude (a ghost) said he needed help protecting the world from this bad ghost who wants to escape. So I went through this dungeon searching for 3 vials. When I got them the blue ghost asked me to pour them in a large Urn, then sit on the throne. So I did. Now this bad ghost comes out of a coffin and is shooting me with blue lighting. I swing my axe and it goes right though him like air. No damage. I die. Repeat ad nauseum....

that does not sound right. you should be able to hit him with your axe.

use shouts and magic to see if that hurts him if not..... it's bugged.