Just bring Quana to 1 HP ("living on the edge") before blessing her - you will easily one shot her with a party member with enough initiative.
My mindset for combat in this game is that the combat here is actually the complete opposite of what it is in other games... in most games today it's about "omgroflulz headshotz1!1337", here it is about solving the puzzle, the riddle a combat situation is. Like chess, but with fancy animation, magic and in 3D. Which is very enjoyable, I would LOVE to play arena, if I could connect to it.
Besides that - if you happen to forget the combination between playthroughs and / or have no lockpicks, you can always use thievery to get the information and the key to Surreys tomb from her petrified body.
As I said: Cheesing or avoiding the fight isn't a problem. Taking the fight and enjoying it
is, because of how massively unfair it is designed.
I didn't even bring her down to 1 HP. Just destroyed everyone in the room while they were still petrified and got full exp + loot. I would have prefered to fight them head on and test my party. Except that all those immunities and dominates they throw around doesn't leave me a chance to do anything. Not with this setup at least... perhaps if I was power gaming 4 backstabber scoundrels.
