http://forums.elderscrollsonline.com/discussion/97595/in-progress-known-issues/p1
I hope the known issue in Hall of Torment isn't that. Really.
I've just did this quest and I died only once (against the Duchess of Anguish).
I chose Lyris and my build is:
Khajiit Healer lv. 30
Active abilities;
Unstable Clannfear III
Summon Restoring Twilight III
Rapid Regeneration III
Combat Prayer III
Passive abilities:
Restoration Expert 2/2
Cycle of Life 2/2
Evocation 3/3
Recovery 2/2
Spell Warding 1/2
That's it for the combat abilities, since this is my crafting character.
If you didn't notice: I don't have an Ultimate ability and I have only 4 skills in my bar, 2 for summoning minions, 2 for healing.
I'm not a pro.. If a khajiit crafter and healer can do this, you all can do this easily.
Just fix the bug of companions (sometimes they do nothing in combat).
Guys.. L2P lol