I was thinking about one of my sci-fi worlds; About how humans might defended themselves before they had chemical weapons and gunpowder.
Mankind is not however a creature of natural weapons. In our bodies their is no great weapon hidden, It is within our minds that we find our truest strength. Through our curiosity we learn the secrets of the claws we don't have, and from the earth around us we are able to craft ourselves means of cheating death that are unintended by nature. Enter the Ceremony.
The vanguards of man take within themselves the disease of their enemy and bind it to their flesh through their scars. The men become Pariah; beasts no longer able to live in the world of men yet crucial to humanity's survival.
Aesthetically this was partially inspired by Diablo 3, admittedly, but the story wasn't ripped off of anything in particular. It only sounds like it was because it's generic genre fodder.