it is the pup. you also need to have the 3 potions in your inventory. did you put points in the jotun skill too? or defend3?
also, since you dont have defend3, you need to change a little your order in the fights so that you block the jotun's strong attack (every 2nd attack) once per round (you cant block every strong attack).
on odd rounds use
pup->regroup->regroup->defend->tagteam->trueshot
on even rounds use
pup->defend->regroup->regroup->tagteam->trueshot.