So just to clarify before we all whinge at each other for being the biggest noob and not knowing what mobs do what - you are talking about the packs of undead mobs after you kill Skadi. The melee mobs who fear and the necromancers who summon adds? There is about 5 packs of them total at the end of the instance.

You are also saying that these guys just chain fear nonstop after patch?

Will keep it in mind and report back if I get UP tonight.