[Douman considers for a moment and then taps the nose of his mask.]

You aren't the first monster that's literally wearing human skin that I've encountered. Let's just say that most youkai have a way to "tell" if a person's spirit energy is normal or not.

[Smell is the most common one, followed by sight. Douman won't tell Fandaniel that his own senses for those things are rather dull -- for a human they had been exceedingly excellent, but compared to many other citizens of the Supernatural they are hardly anything to write home about. Still, he has dealt with his fair share of corpse manipulators, possessing-type spirits and what else of that kind, and the way Fandaniel had acted during their fight had just been.... 'off' in the same kind of ways, somehow. It's really more a gut feeling, or an instinct, that's nagging at him claiming that the other doesn't seem to care about his body quite like he should. It's as if the spiritual energy sometimes moves just one frame before the actual body does, but you can never quite catch it right. So it's more of an educated guess mixed with a bluff what he's selling as confident knowledge here.]