What can I say about humans that you already don't know? Humans can be nasty evil things, but can also be sweet fragile creatures. They're your typical run of the mill average Joe. These are just normal people with normal jobs trying to get by, though many end up learning of the supernatural and end up either becoming Vampire or Werewolf hunters. Hey, these people are lucky though, they get to live normal lives and maybe even die a normal death, ya can't say the same for monsters. Many humans have taken it upon themselves to hunt the creatures out there, it being considered crazy but without them many more things would walk the earth and countless lives would be lost. In the end, most if not all humans can be easily killed.
The Supernatural Intel Agency is a very old organization that once only wished to learn more about the supernatural, and help those with gifts live a normal life. Nowadays that's all old news as the SIA just want to keep them under control. They have many gadgets to help them deal with the supernatural, and they've managed to brainwash and control werewolves to act as their "hounds". Not all SIA know everything their organization does. It's quite possible for someone to just want to keep humanity safe and not necessarily want to harm those with gifts. In the end, the SIA tend to capture and kill many supernatural beings. Characters a part of this organization are allowed to be made, and with admin approval you may be allowed to come up with technology they may use against different beings. Be sure to read up on all the different supernatural types, to see what the SIA do about them. All positions are open for the SIA, and below just keeps track of SIA teams as they usually work in groups of two.
In some religions, an exorcist is a person who is believed to be able to cast out the devil or perform the ridding of demons or other supernatural beings who are alleged to have possessed a person, or a building or even an object. An exorcist can be a specially prepared or instructed person including: priest, a nun, a monk, a witch doctor (healer), a shaman, a psychic or a geomancer. As long as they have strong faith in their methods, then they will be powerful against demons.
The more people who believe in a method will make it more powerful. For instance, Catholic Exorcists are a very well known method to deal with demonic possession and because of it gives their methods more strength than a more obscure way. In other words, individual faith is important but overall faith of people in the world also matters.