I think renderman had the "fnaf element" before FNAF itself but correct me if I'm wrong.
Whatever changes there would be it would be great if someone remastered the Renderman mod so that he doesn't do stuff like go through walls and fix the events that change difficulty/spawn rate.
I would say it had the slender element more or less, considering the post of Chrisbot6's addon was dated around November of 2012, the slender game being around June of that year (Or I could be wrong, but I don't know of any other horror games before or at that time that had the "teleport when you aren't looking" effect aside from SCP Containment Breach)
...but yeah, I'm sick of the constant loud sounds from that addon (and generally everything about that addon), especially if you are on "nightmare" mode...