so the later explanation for why yami was all screwed up in the early manga, was that he had snapped from the isolation of being in the puzzle, and that once he was used to /not/ being in the puzzle he mellowed out. since i agree with you that him being an entirely separate entity from yugi was a retcon, how do you suppose that would have been explained if it just played out more naturally?
Oh ho ho, Nonny. You dunno what can of worms you just opened. *cracks fingers*