For example, some peasants could be found in Ccoa's Sanctum, looking for that damn cat who destroyed their crops. They also could use at least one ability, what about a Ghost Bite reskin called Pitchfork stab?
For Turdak's sanctum and undead or necromancy related packs would go nicely some plain old school Skeletons. They could have similar to Turdak set of resistances, just swap dark immunity for weakness. As for abilities, they could just use their claws. Or if you feel particularly evil you can make skeleton archers.
For Baphomet's sanctum and late game holy packs templar knights would do the trick. Mini versions of Madevra, who wouldn't love that.
For nature related packs and sanctums you could add shamans. Not sure what they would do though, maybe give them some support abilities like cleansing dance and normalizing rain, not too powerful but still useful, shamans are well known for summoning rains with their dances after all.
For anomaly I had this mimic idea; what about a formless gooey mob without any abilities but with very very high speed, it would mimic the first thing it touches, including stats, level and abilities. They still would keep their minion status though.
