Here' a cool idea:
If Shax could partially take away senses, then it would open many possibilities. Imagine a scenario where you do not get stunned, but your body stops regulating heat because it does not feel getting warmer. You don't sweat, so you might end up overheating and collapsing. You might think you are under some binding spell, or mind spell, but it was just your own body sabotaging you. By the time you figure that out it might be too late, so cooling yourself with magic could not be enough.