"Riiight. A skin mage? A hair mage?" Actually, that would be pretty funny. Also gross. And creepy... so maybe not that funny.

"You know a lot about this. Even for someone who hunts demons. You're not a mage yourself, are you?" It's possible where the Handler is from mages are allowed to do that sort of thing. It seems like a bad idea to him, sending someone most at risk of possession after demons, but maybe if he works with a Templar. Or something like a Templar that exists where he's from. Clearly the man isn't possessed and he's managed to grow pretty old doing what he does so he must know what he's doing if he is a mage.