I take them as the 'me' and the 'other me'. Sounds both simple and strange. However, we know that it is possible to get rid of the 'other me' (the devil in you), but once the 'me' has lost his head, by means of whatever, the 'other me' can't hardly exist any longer, it dies with you, it has to cos it is part of you. In this way I understand the intro. Both 'me's get separated and equipped with a different look and a different appearance to strengthen the fundamental differences in the characters, it's the battle of good vs evil - within. If not, well, then I take it as given and continue playing.