[Messianic]

This doesn't seem all that different from live. My 60 epic monk avoided casters like the plague - even ones 20 levels below him. And swarms can be devastating, even if they're level 25's - particularly if they're backstabbing mobs standing behind you (easier to hit you).

The rules that PCs have that prevent them from killing mobs much higher level than them don't apply to NPCs, unfortunately.

Boil blood is as close to unresistable as it can really get.