damage thing which is what kills him

I completed this quest at level when I was 81. The trick I found was to avoid the flame wave and just let the npc's acheter wow gold kill the adds or if you can kill the one you need while the flame wall was going.

As soon as rag pops up let him cast 1 searing flames or w/e it is he casts then get into melee and hit him. He should stay focused on Cen and not cast the flame damage thing which is what kills him.

Hope this helps.