i cant remember where i heard this, it was either forum or newsletter, but someone said that twilight town is "the other side" and that namine and BHK are sora and kairis light sides. think about it. anyone who loses their heart becomes a heartless, but like as kairis grandmother(?) sid in the first game, "there is still light in every soul" or somethin like that. the light travels to the other side, or twilight town. when kairi lost her heart the night of the island seige, her light was sent to twilight town, and became namine. thats why namine could base herself on kairi in soras memories so easily, because they're each other's reflection. when sora sacrificed himself for the princesses, he became a heartless, so his light was sent to twilight town to become bhk. even though they came back, their light also stayed. this also could explain why tetsuya nomura (producer spelled wrong) said that soras clothing is important in the second game. sora has no light left. hes lost his innocence. i know this has been long, wtv.