Anyway, once you've got your hero or heroine in mind, make them evil and then write them into a story. What happens when the good guys turn to the dark side? Who will stop them?
Ulterior motive
I was talking with a friend over the weekend about Kindle Worlds and fan fiction in general. I mentioned in passing that I thought part of the allure of fan fiction was that the universe was already created, so writers can concentrate on telling a story rather than getting caught up in world-building. It also saves them the trouble of having to introduce and develop their main characters.If writing a novel from scratch is like writing a symphony, then writing fan fiction is like improvising a jazz solo: You can't change the underlying structure or the main melody, but you still have a lot of room to play around in.
There isn't a lot of space to make a living writing fan fiction, and the legalities of even trying to sell it give me the howling fantods. But still, playing around in some other writer's universe can be a good writing exercise.