1. Faction name
The Bringers (of the apocalypse)
2. Faction morality (Good, bad, neutral, etc...)
Anarcic Nihilists (evil if you want to simplify it)
3. Followers.
No census taken, but very low
4. Allies.
The Bringers have no Allies. They may have temporary alliances agreements but their parters do not know they're dealing with the Bringers (and likely have not heard of them), any deal will likely be followed by a double-cross from the Bringers. For their part, the followers consider the Bringers friends in need of treatment and will go to any means necessary to provide it (including letting innocents die to use non lethal means on a bringer)
5. Enemys (Must have at least one)
The Bringers consider all of humanity, including mutated humans, their enemy.
6. Location
The Bringers have no official camps, but at least 1 can be found in any given followers of the apocalypse camp
7. Technology (Wepons, armour, etc...)
As per the followers of the Apocolypse
8. History
Each Bringer has a tragic tale, but they all share the same common points; after their goodwill was misused, after constant mistreatment, and after observing countless crimes, some followers of the apocalypse have strayed from the fold. Becoming disgruntled some come to (or are lead to by other Bringers) the conclusion that mankind should not be saved, that the apocolypses only failure was that it left some hearts beating, some lungs breathing. They believe that dispute the good (seen as naive by the Bringers) attempts to restore the flame of civilisation, their attempts are hopeless and the candle should be extinguished once and for all.
Eventually enough disgruntled followers came into contact and began to use the followers' organisation against itself. Some poison supplies, others use their knowledge to commit genocide, others pass dangerous knowledge and technology to those who will use it's distructive potential. The Bringers work in secret, watching their colleuges in the followers for possible recruits whilst keeping up the charade of being a happy follower.
The followers for their part consider the Bringers mentally ill and therefore redeemable with correct treatment. Senior members are aware of the Bringers, keeping their existence secret in order to protect morale and stop the followers from self districting (as would surely happen if their existence became public) whilst diverting more resources into mental Heath treatments and monitoring their staff for signs of disgruntlement.
9. Optional: Quest (To get in, to earn its perks, etc...)
To get in: you can't. You may be asked by a bringer from time to time to act as a courier.
Toward the end of a game, the Bringers provide a faction which the PC may be working with materials for a nuclear bomb. If the PC does not discover the Bringers plot, the ending slides will indicate a massive war followed the blast as the Bringers had provided forged evidence to every major faction that the nuclear blast was a part of a conspiracy by the other factions, and they're next on the list!