It is always interesting when humans dabble with demonic energies. Of course finding a demon to pact with, to feed them those energies is not easy for most, but occasionally they manage it. Most humans burn out fast with such potent power flowing through their frail and unenforced bodies. There is the occasional human that seems to have a real knack for it. I've collected and studied many of them, and there seems to be a fundamental difference not only in their body, but in their mind. 

Still, even with these prodigies they are so inferior to the average demon it is hardly worth the effort, aside from novelty.

I have recently acquired a young human who is so adept mentally that only her inferior body is holding her back. I think, with a lot of blood, sweat, and tears I can push her to a whole new level.

What can a human become, when stripped of their humanity?

-Writings in the archived files of the Master's workshop