When I write supernatural stories, I do so based on a backdrop of a supernatural world, which I call the Demon World.
What this allows me to do–besides creating an entire world from scratch and populating it with all sorts of malevolent entities that represent in one way or another my understanding of evil–is create demons, monsters, and villains with a rich history and very particular motivations. This, in a sense, protects me from the danger of making my villains into caricatures, for it demands evil be motivated. The idea of the ‘for fun killer,’ for instance, is–to my way of thinking, at least–rather shallow. People do not kill because it gives them pleasure, as such; it gives them pleasure because of the emotional state they happen to be in. People who enjoy killing do so because it makes them feel god-like. What this requires, however, is that in their normal emotional state they feel quite impotent. It is this impotency that fuels their rage, which manifests itself through violence, which in turn makes them feel powerful, which causes an euphoric feeling–pleasure. Taking this dynamic of potency and impotency, and applying it to fictional characters, has allowed me to create–I hope–much more well-rounded and believable characters, with their own hopes, dreams, and aspirations–even if these are dark ones.