If you've ever loaded a saved game and had one of your guys completely immobilized, it's from saving a game while casting a buff spell. I encountered this while buffing up before one of the demon fights. This is also true for NPCs buffing out of combat. After talking with Belsornig, I saved the game while he was casting one of his many buff spells. After reloading, he was stuck frozen, and never took an action during combat. Although if you talk to him first, then attack, he comes back to life.
