This was actually pretty easy, as a sorcerer, not even that time consuming. Perhaps they toned it down. I played it just like any other "hard" npc, i.e. mainly healed khem and kept him bubbled. the only diff was I had to heal myself a bit, and bubble myself, because some of her effects hit me too. Also, as others recommended, I used my two interrupts on her from time to time, when she was casting something. But I ended up with both Khem and myself at at least 50% health. Didn't have to hide behind any pillars or anything either. I'm sure it's more difficult, of course, with an inquisitor specced for tanking or dps.