In the We, the Afflicted mythos universe, a group of eldritch abominations known as Higher Beings has decided to take several humans twist these humans into humanoid abominations known as the Afflicted, as a plot to try and create stronger, more dangerous Proxies to serve him.
There's just one problem: these humans didn't quite break in the right way for proxification. Many did, but not all. Whether they had some innate quality in them that made it so, or just didn't snap right, some of them ended up rebelling and escaping. Amongst one of the first to do this was the Weeping Willow, a once happy woman who now weeps into the branches the Slenderman gave her. Some of the beings followed in Willow's footsteps, some fled to their own hideaways in all corners of the globe, and some stayed with the Slenderman.
As a result, power battles and competition have been set up between these new eldritch beings on whom claims what of the world, of humanity, of everything.