An interesting point you bring up. I've never really thought of souls as being light or dark, but maybe I should have at some point. I've always just thought of a soul as being like a standard issue type thing that we all get, but looking around at the really evil beings of the world, some of them give me the feeling they're SO damned evil that there had to be something wrong with them even before they were born.

Maybe those types are honored in traditional Hell. I don't know but it seems like a possibility.