[No spoilers]How to deal with Magister Vorrh shackles of pain ?

He managed to perform shakles of pain on 3 black ring soldiers in one turn and then in the next managed to put one more on my conpanion. It's really annoying and game breaking specially since so far my blood mage can only perform 1 and I don't think there will be more.

I wanted to save those three members but these shakles bs is beginning to annoy me.