Nobody is so dangerous because he defeats evil spirits without them even realizing it's happening. Usually they'll try a battle of wills, or attempt to slowly infiltrate the mind, and if they start getting weak they'll flee, such as when a will is stronger or a magician of any sort is assisting the removal.

Well nobody does to them what they do to others. He makes them feel stronger as they grow weaker, and they have no chance to run. They become another chain link in his armor.

Have ALL of you forgotten the best use for an evil spirits in days of old? You put them on little wheels and make them into armor.