[Yossar]

Depending on how much they invest into buffing MR, a few mages casting charm/hellbind heart/control the dead/soul slay with a rune smasher and spell focus can be fun. Otherwise I like a bunch of demiliches with a skull staff and boots of quickness with some lifeless chaff in front of them (mechanical men or lifeless undead maybe) spamming drain life. Or enough illithids can eventually paralyze almost anything without ridiculously high MR. And once they're paralyzed you can chop them up with anything if they don't have astral shield/fire shield. If they do you probably need tougher troops or your own mini SCs.