"He's right you know" said Kamiko, when she noticed Kat's slight disbelief. "It's one of the things we're told about if we so much as glance in the direction of learning how to enchant. Demonic enchanting draws first on the energy in the demons nearby which is fine, we put off a lot of extra energy but the problem is when it needs more then that. It starts going after whatever it can, and if it absorbs mana or qi… strange things happen. It's a weakness to our enchantments but not one we've ever been able to fix"
"It's worse than that actually" said Freddy jumping in. "Other kinds of enchantments will just stop working when they run out of energy. Demonic ones won't ever have that problem. They will try and use whatever they can to keep going even as that warps them. That is, until it fails catastrophically."