I have been thinking about something. As stated long ago, the only numbers not in the operation of 358/2 are 4 and 6, which would be Zexion and Vexen. To explain, 358/2 = 179, and in order that's 1235789. Well, I started thinking and I'm wondering if Zexion and Vexen could still be alive. I mean, other than Xehanort, those are the only other apprentices specifically mentioned in Secret Ansem Reports. Also, they both have the means and it wouldn't be too much of a stretch if they both were. Vexen, for instance, could make Replicas of people. As Axel said, he didn't like to show himself topside. Also, he is, by his own admission, a scientist, so odds are he probably tested out his replica process on himself first before moving on to others. He coud have just sent a Replica of himself to Castle Oblivion, and ,although I'm sure if it is canon or not but, the manga would basically support this theory. Then, we have Zexion. As we've seen, Zexion is very smart and likes to think steps ahead of others. He saw Axel basically 'whack' Vexen (or some replica of him), and he had to have considered that Axel might do the same to him. We also know that Zexion didn't really like to fight, and he could create clones of himself. He could've just left a clone of himself behind with Lexaeus, and high-tailed out of Castle Oblivion. This would explain why he was 'defeated' so easily by Riku and the Riku Replica. I know this very unlikely, and pure speculation, but I'm a OXIII fan and like to wonder if some of them could have survived. So what do you all think about this theory of mine?