Odd, I had no issue with this fight at all. I think I was level 15 at the time and won on my first try.
What is your party like composition wise? Is this on Tactician? Do you have any high-health party members?
Have you tried spreading your party out? I remember moving my other party members to the above position.
Do you have the necromancy spell to prevent death? Could try casting it on the person in conversation.
