Depending on how the patch leaves the state of instances, Pets can be sick'd on this and swarm pets, but it ae's a small range Dot that will own them so its hard to kill.
And there are hacks that show all sorts of information about zones/mobs that shouldn't otherwise be available to the client... or at least there used to be, I've heard a lot less about them these days than in days of yore (I always wanted to say that).
i dont know for sure, but some spells only work on mobs up to a certain level so if a spell works on a mob that is 80 but not on 90 then that might work