Has there ever been an explanation for Shinigami having an inner being inside them that is a Separate consciousness, and yet spawned from their souls /whatever?

Do all Sentient beings who don't become hollows, and have a high spirit power, turn into Shinigamis?
Hollows may have a Second release, but they don't have an inner self to argue with.

Will the undearly departed Fullbringers qualify as Shinigami as they are right now, or maybe they could develop an inner being and become shinigamis later.

Any thoughts?

Quote Originally Posted by Jaiden View Post
Well since he has access to his full powers now it kind of makes sense that he does have new clothes to channel his full powers.
Guess I am infatuated with Ichigo being so different from the others, to where he doesn't need some of the aids they depend on.