[@LadyinInk] Wanted to ask, do demons differentiate from humans in the aspect of having a tainted/no soul or just physical mutations and lacking empathy or both?

I was thinking of some backstory for the Golden Claws organization. Was thinking of them being as the guardians of the Human Controlled territories. They build monastery/fortresses on the far outer reaches of the occupied territories, defending them from wandering or attacking demon forces. If they get notified from a village or settlement of some demon attack they send a squad of trained demon hunters to deal with it. And every year every settlement is obligated to send a set number of young boys aged 8-14 for them to be trained as demon hunters. 
Demon hunters can easily discern demons, especially shape shifters, half-breeds, anyone with demon taint in them from normal humans. They are trained rigorously both physically and mentally in order to match a demon in a 1v1 fight and resist their psychic attacks(illusions etc). Their bodies are marked with tattoos and a ritual is performed to give them special abilities that nullify all forms of magic. What level of magic one can void depends on his training level and age. Fully fledged ranking Masters, like Numenor, can nullify even the most powerful of magics.