I not understand why you think is so hard. After i see the levers for deactive the two healing chambers is was very easy. I killed two time one with mage and one with warrior level 27-28 i not remeber with a very easy way. You need simple ignore the summoned enemies lower the raze healt nearly the limit he go to heal, save for be sure, and go to use the two lever and now use all the thing you have and kill before the chamber go on another time.
