Hi,
I'm reading through the magic section a bit more carefully and the control spell says nothing about attacking controlled creatures. Am I off point thinking that an attack should allow some kind of "save" for the target, perhaps an unmodified or difficult Idea roll? Otherwise it would be no problem for a group of characters with a high-POW wizard to hack away at fairly powerful creatures for 10 combat rounds, probably an easy kill. Thinking about Giants (POW 11-13), Dragons (POW 20 - still a 40% chance to control for a 18 POW wizard), Greater Deamon (POW 16-17), etc.

I may be totally off base, haven't actually played the game yet...