I felt I should add to this as a level 34 thief who just killed the abominations (and is still in the mission) I literally just got murdered by the two abominations. When I switched to my bow and sat back shooting at them, I noticed they both had 25 stacks of their buff and one shot me any time they so much as used an area attack to hit me.
Also, their smash attack hit such a large area it would hit me unless I timed the dodge to happen at the moment of their attack. Being out of visual range no longer worked.
Did the buff boost the size of their aoe smashes? or was it just larger than the ones in the swamp?
I died enough for two pieces of armor to be broken. Also, Ihan was bugged out for the entire mission so far.