The Cultists
Not much is known about the Cultists as they are named by the UNDF. But the few we know is terrifying. They are able to control the Virus, modifying it at their will. As rumoured, they worship the Virus, and the highest members of their organisations are the ones who have been the more mutated at their will. They are very aggressive against the "Infidels", humans who are not worshiping the Virus, often raiding the cities and trains convoys.