Life, in its simplest form, is entropic conversion. Energy is gathered, and then utilized. All that energy that would otherwise simply bounce around endlessly until it is the finest warmth, is instead bound and USED.
But "free" energy, although unlimited, can only be accessed by certain life forms.
However, every living being that hoards energy inside them, ironically, becomes a source of energy.
The carnivore that consumes a herbivore becomes stronger for it, but the process is wasteful.
To gather and consume "mundane" energy is one thing, but to gather and consume magica... now that is another level.
The whole world is rich with it, but to feed on the raw source is impossible, for us. Just as the beast cannot bite at the sun, so we Demons cannot simply soak it in directly.
Humans, ironically, do soak it in. They can use so little of it, but their meat is rich with magica.
But what if we could bypass them? Funnel it all directly into the Demonic body. ALL of it.
It would have to be done so carefully...
but what then could we become?
-Notations in a lab, by the Demonic Master, The Head Master