I've been getting into tabletop games such as D&D and for my birthday I got a game called Mutants and Masterminds which is a superheroes rpg and I love it so much :D
It's been helping me create interesting scenarious and villains and all sorts of fun.
Has anyone ever used a tabletop game or rpg to make your heroes or storylines?

No. Can't say that I have. However, I got an app for my iPad and I started to just profile my characters. As I was doing it, the stories in my head came flowing out. It organized my stories by linking the connection between characters.

Back when I was a teen, I use to replace the marvel characters with my own and had a ball reading them. It forced me to think and create my own universe. It helped create almost have the characters in my universe.