OP here. Here's a little something to get things started off.
On paper, where it appears at all, SCS stands for Special Countermeasure Service. Very few people know the truth; that the first S stands for 'Supernatural'.
Things like werewolves, vampires and sorcerers exist. For how long, nobody is quite sure, but it is only in the last few decades that any hard evidence has been found.*
Perhaps these things only recently came to exist. Maybe they've been in hiding. Nobody is quite sure.
All over the world, isolated incidents alerted governments to the presence of the occult.
Bizzare ritualistic murders in Germany; a team of British soldiers killed on a training excercise with the only survivor reporting werewolves; A sudden spike in campers reported missing in America's national parks, some turning up drained of blood.
As these incidents stacked up, nations gradually realised that they weren't facing isolated incidents, but a golbal problem.
*And carefully covered up, of course.