I just worry when people talk about combo units in general. I'd hate for every unit whose primary purpose is to affect allied units to be lumped into the "bad for Zatikon" category.
Archangel can only be permanently dealt with if transformed or stolen. Possessed needs to be stolen, killed by inorg, abjured/purged post-possession, or rocked. They require people to include units from a very small pool of foils.
Or killed by gate guard on the castle. This is an important point for random, which always includes one in every army. Admittedly, you sacrifice a ranged unit to do so, but it's almost certainly worth the 400 points of possessed.