'Horror' is subjective per say. Not everyone can be afraid however I find that horror thay relies on jumpscares and chase scenre for their whole mechanic are an annoyance. I tend to prefer pure horror by storytelling and the execution on appearance, plot and atmosphere.

Best advice is just to watch tutorials and experiment a prototype for fun. I don't technically advise to put a game public without figuring what type of RPG Maker game to make and how it would go about.

I mainly use MV however not much of a difference than partial limitations.