Yea i dont think the havoc one is very difficult due to how fast DH can be, probably is aids on the frost DK.
for some reason the feltotem one has disc priest as one of the classes attached to it (BM hunters, Destr warlocks, WW monks, disc priest) and i know they have issues getting it down.
I guess next time the tower is up i'll try Agatha on my warrior since i mainly play him as Fury these days. Not going through the tank challenge fuckery again until i outgear it, even though the warrior skin is pretty legit.