Re: KH2 Ending Discussion Thread ***Major Spoilers***
I have a theory, though it's rather long.
Heartless are born of the darkness in one's heart, correct? And Nobodies are the discarded vessel (the body & soul) when a being loses its heart. But what is to be born of the light that resides within the heart? If the darkness is seperated from the heart, surely the light is as well?
These beings of "Severed Light" could be referred to as Chasers, or independant entities with the sle intention of seeking out the components of their former selves and reuniting all three pieces. Unfortunetly, my theory does not end there. =D
What of the abundant amount of keyblades that simply dissolved into nothing, the so dubbed "Keyblade War"? As presented to us, it seems many people can wield a keyblade at once, though this concept is not fully understood. Though there can be many keyblade weilders, there cannot be more than one Keyblade Master, ex: Sora.
So, the Keyblades seen at the crossroad could have belonged to those of lesser hearts, and simply dissolved in the presence of a stronger heart, possibly that of the first Knight to appear, seen wield his own Keyblade before drawing the Kingdom Key.
The three beings could be Chasers, possibly looking to reunite with their other entities, who I believe could very well be Sora Kairi and Riku, though doubtful on Kairi's part. Of course, the same laws for Nobodies may not apply to Chasers. Chasers could possibly posses a different gender than the original entity.
The final being to appear, the fourth, from the dust, could be one who is either opposed to the others, or seen as a Superior. But either way, why would they take up arms? Because Xeanhort's Heartless and Nobody were both defeated in the presence of Kingdom Hearts.
Would it not be possible for him to be absorbed and reborn as another corrupt entity, utilizing both powers of his Heartless and Nobody? Seeing their Others as currently unfit to defeat this revised Xeanhort, the Chasers could be seeking out their originals to reunite and resore them, much like Roxas to Sora.
As for the armor that the Knights were encased in, I believe they were created in the same manner as Xemnas' armor. Through the abosorption of some of Kingdom Hearts' power. This could mean that the knights have either seen and sealed Kingdom Hearts, or have opened it for selfish purposes, though the latter is unlikely.
EDIT: I seem to have forgotten King Mickey's Letter, so I will add that in now. The Letter could have either been a warning from King Mickey stating that the compilment of "Xeanhort Memories" had returned, and that they would be best suited to prepare themselves.