I believe everything exists in some way, shape or form, and the very act of believing in something gives it life in your mind. The more people believe in something, the more powerful it becomes. Ideas like God and Satan are incredibly powerful to those who believe in them strongly enough. It's the same with all ideological figures.
Personally (right now anyway) I create figures that are something like tulpas that I use to help me keep myself busy and to make me feel like I'm doing something productive. they aren't as fleshed out as a typical tulpa, but they are there when I need them.