This is, a more dark version of what I think happens in the future with the creepypastas.

Please specify if you want to do a time warp or use a next gen character as well please

Slender basically thinks it's time for a new generation of killers to start up, so he kills the old generation, only keeping a few, and taking the children of the last generation to a new mansion.

But this time, a more systematic approach.

Different rooms for different types of killers, the violent ones, the dark artists, puzzlemakers, and whatever.

Each of the kids have letters and numbers on them, along with slenderman's symbol right next to it

Ex: TE00101
Parent's first initials, first born (or otherwise), "class" they attend