I'm being seriously frustrated with fighting enemy blood mages in Dragon Age 2 (currently Huon as part of On the Loose quest):
They're casting some kind of death cloud spell, that appear as a red fog circles on the ground and stuns my party members in the area and does a lot of damage - my main char (mage) and Anders and Isabela die almost instantly from it (and die certainly in a few seconds thanks to the stun).
I already had the same problem with another fight and I somehow managed to fight through it by lowering difficulty.
So the question is: how do I avoid this ability / mitigate the damage / counter it?
I'm playing on Hard difficulty.