...okay, I figured it out.

I went back in there last night and solo'd the same mission with no problem. Apparently, the 'Anathema' have a ridiculously powerful melee attack, so if I just immobilized them first I had no problem (because their ranged attacks are weak -- 40ish damage instead of 250). I got so used to fighting Tsoo and council and vaz and the weaker Lost (who have powerful ranged attacks and 'eh' melee) that I got out of the habit of using Chillblain (my immobilize) -- the DOs in it were *red* because I'd never replaced them.

Then I got into a pickup group which ( sucked. )

I went to Talos Island and did some soloing, hovering over groups of melee-focused enemies. The 'Warriors' are basically Hellions, they have to pull out weak little pistols if they can't get into melee with you. Easy prey.

Eventually, a mission took me to ( Striga... )

( Where Tom's illusion controller made me jealous. )