At least someone else cares.
My best guess was that he auto-casts MoD, though in the second battle, the Mist effect doesn't come until late in the fight. Every time they cast Phantasmal Warrior and Ghost Wolves, it adds more spawns each round at the sides.....
Honestly if someone tries to tell me that is just how MoD works, I'm going to laugh. I can't imagine how fast almost anything would be totally overwhelmed if you had say 10 casters spamming Ghost Wolves like that. o.O