Forget about hypnosis; it can even be dispelled with a level 1 magic spell. And it also has a drawback. Here's an example from my last battle. The enemy's Mage hero, instead of casting something useful, cast hypnosis on my already weakened Monks. Immediately, the turn of these now-not-my monks came. He moved them and attacked my Tactician, but only took away half of his health. And that's because you can't shoot at enemy units with hypnotized units. It's a useless spell.