The Demon is missing one himself, though not because he owes anyone money, but because Ethan is a dumbass that let himself get caught by a serial killer. And what happens to Ethan, is replicated on the Demon.

"That's a shame, everyone could use a few disposable people between them and danger." He tilts his head, trying to imagine the kid wielding a sword. "Soon it'll all be internet attacks and identity theft. And then what will you do?"