REPAER'S PROFILE

I was thinking of making an horror themed RPG. One thing I could not wrap my mind around is how to combine the two to make a decent RPG.
I haven't thought of any story yet, because I am thinking of game design first. I would like some ideas like themes, settings, or game play ideas to help me start thinking. I will be using RMVX so keep that in mind while you suggest ideas.
Thanks