I found something wrong with Olympus Coliseum in KH X. The characters don't match the chronological timeline. Hear me out. This game comes before BBS. In BBS, everyone was younger if they appeared in other games. So, shouldn't at least Hercules be an infant? And how do you explain Cloud's appearance? I get that most Disney movies don't respect age, but Hercules portrayed the entire life cycle. Plus, in BBS, Herc was a teen, and Zack was younger than when he met Cloud in Crisis Core (Final Fantasy VII), in which Cloud was younger as well. Am I missing something? Well, I guess if there's time travel in DDD, then there could be alternate universes in X. Not to bash the overall game, but I think Tetsuya Nomura failed a bit on this aspect.

 

The game offered an explanation a while ago. It's suggested that the Tome of Prophesies has the ability to create illusions of other worlds from different points in space and time. So all the worlds seen in KH X other than Daybreak Town are all illusions, fakes. They aren't really there. The exact location of Daybreak Town has recently been put into question since Chirithy might be a Dream Eater, but that's a different topic for another day. Anyway, with that being said of the Book, that would mean that the Olympus Coliseum seen in KH X isn't the real OC, just a facsimile of the world with it's own events. It's not the real OC that Terra, Aqua, Ven, and Sora would eventually travel to, and the events that happen in this fake OC have nothing to do with what happens in the real OC in BBS, KH, and KH2. There's so far no such "alternate universes" that can be acknowledged and Nomura is pretty on top of creative things in his games' stories when it comes to big details like that (although 1 or 2 little things have been up for debate, but that's also a different topic for a different day). So Nomura didn't fail in anything, it's just that it took some time to begin to explain it.

Wait, Olympus Coliseum is the only one that makes no sense to you? What?

Hero Of Light XIV pretty much gave you the answer, so that should answer your question!  It's interesting how this Book Of Prophecies works, and if Maleficent and Pete are searching for it, it's because they want to make a mess of things!  That book seems to be awfully powerful! X_X  But yeah, Hero's answer should be able to clarify any doubts you had on Olympus Coliseum!

Hero of Light is correct.

I did some further research and found the answer, but now it's even clearer. Thanks guys. I knew there had to be something I was missing myself, since it isn't like Nomura to leave plot holes. Although it definitely would be easier to grasp if it were localized. I'm currently following the walkthrough by Everglow and DChiuch.