When I was a kid all of the animated shows and movies, all the characters were black and white. The good guys were perfect. The bad guys were bad, and that was it. There was no sign of goodness, or sympathy story.

Later on Gargoyles introduced me to anti heros of gray characters. Most of the villians were not pure evil, either there was some good inside, or they had a back story, that helped you understand them better, and maybe even gave them sympathy.

Prime example today is Avatar. Except for Azulla, the Fire Lord, Zhao, and maybe a few others, lot of the villians were gray. Jet, Mai, Ty Lee, and of course Prince Zuko. People do bad things, doesn't mean their pure evil?

Don't get me wrong, you need pure bad guys. Do you like the idea of gray characters?