Looks like any of the dark bone skellies that inhabit Unrest. He doesn't hit very hard and drops the preserved hops for the alcohol summoning amulet for brell followers.
Have battled him twice now, once with Weapon sheild up one without. We are 1 to 1. Even slowed he hits hard at around a max on me of 3k, but it comes in trips, back to back, which can devistate my ranger buttocks. I did not notice a DMg shield on him but we pulled him right when he poped both times in the courtyard.
You can dispell the damage shield. I have done it repeatedly. The exact amount has to be higher than 450 tho since my bst's hp's were going down like crazy when DS was on..