A good theory, but I disagree. For all representational purposes, shouldn't 0 be the realm of inbetween? I mean, 0 is the boundary between the positive and negative. Wouldn't it make sense to have the realm that acts as a boundary serve the same purpose with it's numerical representation. Also 0 is absolutly nothing just like the realm of inbetween. With this logic the realm of light would be 1 and the realm of darkness would be -1. If this were true, 0.5 would be some sort of pocket realm inbetween realms of light and nothing. Or it could refer to the worlds like Castle Oblivion/Land of Departure and Twilight Town that sit on the edge of the realm of light, close to nothingness. I think the pocket realm theory is a better theory because it explains the use of "fragmentary passage". What I mean by this is that maybe both the 0.5 and the -0.5 realm have some sort of connection. This connection could be how the casle of dreams ends up in the realm of darkness. If the castle of dreams and the other worlds somehow ended up in the 0.5 realm and were somehow brought through to the -0.5 realm from this passage, the worlds could transition from there to the realm of darkness. This is only my theory, we'll have 2 wait for BBSV2 for the actual answer.
