here's a hint for parties:
If he keeps killing one or two weak members of your party do the following:
+ Buff up one tank to the max and go for Firkraag to draw his fire (literally)
+ Meanwhile sneak the rest of the party out of sight
+ When your tank is nearly worn out, buff up another tank and send him in, meanwhile fleeing with your first tank
+ Heal the first tank and when the second is down to little HP buff him up,etc.
Kind of a Tag Team tactic