The first thing I was interested in here was the presumed weakness of Abyss Warlocks vs. undead. I'm sure other people have figured much of this out, but I don't recall it being posted so I thought I'd offer my experience as a Public Service Announcement.
I rolled up a Deep Gnome in order to test whether there were any synergies between Abyss Warlocks and PMs. The answer seems to be for dealing with undead, not so much.
The obvious connection between the two is the use of negative damage for pact blasts, PM's negative damage SLAs and Unholy Avatar, and I was wondering whether there was any synergy there. Nope.
I haven't run a PM for quite some time, so I didn't realize Negative Energy Burst and Death Aura don't damage enemy undead either. If you attack undead with a negative damage spell to activate Unholy Avatar, and then use NEB or DA, they suffer no damage. So, there's that.
In other words, my dream of playing a vampire melee running around with Death Aura, Abyss ES Eldricht Aura, and making undead vulnerable to all this negative aura/burst damage via Unholy Avatar? Nuh uh. If you're looking for ways to overcome undead resistance to Abyss pact damage, you're going to need to look elsewhere.
I wonder if the problem arose when Lynnabel responded to player requests to make undead not heal via Eldricht Blast Abyss pact damage (quite understandable). The change that made negative pact damage leave hostile undead undamaged made them unaffected by anything Abyss pact damage does, including a PM-Warlock trying to use UA on them. It seems to be same game mechanic as NEB, DA and LDA.
As a result, UA is much more limited than is immediately obvious. Oh well. Another DDO build dream crushed on the cruel rocks of failure and despair.
It would sure be cool if there was an enhancement or some such that allowed one to override that immunity. A kind of Unholy Unholy Avatar.![]()