I don't think I'm a good person?
Why would you think such a thing?
I just find that the things I've done were bad way too often
Well, it's good to try to see and analyze your flaws. Now you should use that to work on improving yourself so that you're a good person.
I'm researching the methods villains use to hurt people because I want to feel powerful.
Maybe instead try to research how to be a better person and how to help people. You might feel powerful then as well!