Not sure how that's possible since the maximum range on any weapon is 12m and you need to be facing the mobs to attack them. Seems like you'd either attack the mobs because you're not facing Rahabkor or you'd only attack Rahabkor because the mobs are behind you.
He could be becoming untargetable at certain times or maybe he's leashing, but I'm not too sure on that. I'd need to review the encounter and it's our most complex one.
-ALS
Bookmarks