What if this scene is before BBS? But then again it can't be. What if it's in the begining, you just met the others, then this shows up, then you go back in time to where it all started off so you get a better udnerstanding of what happens? But then that sounds like FFX >_< . I play too many viideo games >_< lol. Or maybe, We meet our hero's from our 'master' who trains us to fight, and then he sends all three of us on a mission to find the three 'true' keyblades to destory the darkness. We look and look but then we don't find it, UNTIL we meet each other on a battlefield where we see a whole graveyard of keyblades and have to fight 'The Keyblade Protecter' (that monster in the secret ending in KH 2). Then we find the 'true' keyblades and we run into MX who is also trying to get the power of the 'true' keyblades to open up kingdom hearts.
Just a theory adding to his. And yes, i have a very active imagination.