Passion Project 2.0: Brainstorming

So I have been spending the last two weeks brainstorming ideas. I have to say that I have a fairlly decent amount of ideas. The problem is deciding on which one to use, should I write what I know and tak the route of fantasy and magic or do I write historical fiction which stopps me to a degree cause that requires research and "historically accuracy". also another problem is that they al kind of steal peices from each other