I got a bug with the Doppelgangers. I had two groups of Demons with a group of Doppelgangers between them. I turned the Doppelgangers into Demons, but they were still a separate group. Only when I caused them to move they became a single group.
Edit: just managed to somehow freeze the game with the Priest´s Banish spell. The cursors only showed for one enemy type and the game got stuck when I clicked another one.