Did you take time to read what the boss skills do ? And did you watch what happens when he dies ?

Otherwise you dont seem to actually want any advice so i'll refrain from typing something you said to please dont say ... 

Yes on both. Still have no idea how it happens. Doesn't say it ignores defense or anything like that.

WHy would I be posting here if I didn't want advice?

the boss doesn't ignore defense, but one of his minions does and it hits for 60% of your champions' max hp. the remaining damage from the other minion and the boss themselves sounds like enough to knock out the other 40%.

crowd control is the best method for dealing with this boss, as well as tm control and block revive if you happen to have that.

Yeah that boss is all about just dealing with the minion on the right. Either CC it, or have some other way of getting back up after it attacks. Block revive works well here too, if you happen to have one of the UH champs that do it.

Thank you, THAT would have been VERY useful had someone mentioned it a month ago.

I don't think I have any block revive Undead champs, but here's the decent ones I do have:

UDK

Dark Elhain

Sorceress

Lich

Grinner

Ghoulish Ranger

Frozen Banshee

Nethril

Dark Athel

Gravechill

Seducer (but not Temptress)

Corpulent Cadaver

Sticked Beast

Gorgorab

I mentioned Stitched Beast and Gorgorab last because I just pulled both last week and I really need to level them, any advice on how to do that best would be appreciated. Everything else I'm pretty sure is just junk. 

OK so here's the thing - I wouldn't waste time on randos just for this. Of your list, the ones which are actually worth bringing to 60 are - UDK, Nethril, FB, and Gorgorab. The others are pretty much trash - but the four of those should be able to get you through. Nethril especially - since he can stun the minion on the right, it should just be a question of re-running it until you get the stun to land, and then from there it should be ezmode.

Lich at lvl 50 is part of the Rhazin fusion, so you need to level that one anyway. Lich at lvl 50 would be a good 5th member to the team Krama suggested, his A3 has 100% tm reduce.