#simple replies

Yeah I'm on the same page as you that I definitely think this could be Ava! I even think it's possible that if fake Brain isn't her directly, that it could at least be a program (like data Riku in Coded) produced by her-- though admittedly, that would take much more time to code a program than just disguising herself with magic in a flash.

So, I’m actually 90% done with creating a video (partly) on Dark Chirithy!

So first, I wouldn’t completely rely on what Ira said only because Ira at this point in time does not have the full picture. Ira doesn’t even know for sure that there IS a traitor, he’s only assuming there is based on the dark Chirithy he found. There IS a traitor, but it’s unrelated to the dark Chirithy which belongs to us. 

When talking about the Dark Chirithy to the other Foretellers, Ira says that they dont usually concern themselves with the tools the wielders typically use. That tells me that if anybody gave the Chirithy’s the bangles to give to the keykids, it was the Master of Masters himself. And that coincides with what Dark Chirithy says, that it was the MoM’s intention all along for the wielders to use the darkness as a power. 

So, I think that could be interesting, but I still really think it’s Xigbar. Xigbar writes in Observations 2 that he saw the Five Union Leaders off, so he probably recognizes Skuld when she arrives in Daybreak Town (it’s not confirmed that its her, but like..... lets be real here). And plus Xigbar was in the right place at the right time, he has all the knowledge of the castle and the routine of its experiments and guard procedures. Odin, assuming he’s human, would age like everybody else ( even Xigbar appears to age other wise he wouldn’t need new vessels ), and by that case he would be looong dead by the time Subject X appears in Radiant Garden. The stars just align in my opinion  ¯\_(ツ)_/¯ 

I KNOW !!! I really do hope that one day Nomura creates at least a cutscene movie (cause a whole game may not have the capacity for exploration or mechanics, etc) of all the events between BbS and KH1, including Isa’s X marking. The most we have is KH3 Axel saying something along the lines of “One day the girl was gone, the next we apply to be Ansem the Wise’s apprentices, the next we’re nobodies, the day after that we’re doing icky jobs for Xemnas.” and even that is so vague, it’s tough to get a window of when Isa got that scar. It really would have had to happen within a single day.

Sorry for the late response, friend!!

I think that’s totally possible! The one thing I would say is that Xehanort says the world tour is of “worlds written on in old fairy tales.” So, if Xehanort’s world tour was all the disney worlds of KHX (as they’re projections from the Book of Prophecies), and if Xehanort traveled via dream worlds, it would have to be at a point that all those worlds fell to darkness to the point where they would create a Sleeping World to begin with. At least, this is on the assumption that Destiny Islands and the Mysterious Tower only fell to darkness and got a Sleeping World because of KH1 when Heartless were stealing the hearts of worlds. But if that’s not the case, then it may be possible that worlds fall to darkness eventually nonetheless? But that’s conjecture haha.

Still, I’m willing to put a pin in this! I’m still not sure if Nomura is going to retcon YX’s childhood, by either making so he was younger on Destiny Islands with grey eyes (so essentially, Chess Xehanort lived on Destiny Islands and then went to Scala ad Caelum) or by doing something similar to what you said. He’s story was a little messy already, so for now I’ll definitely be open minded to various possibilities like yours.

So, I do know that in the KH3′s Ultimania, Sora is still stated to be 15. But I hate looking at Ultimanias for answers, so let’s talk about in game evidence LOL

First of all, Sora in the beginning of KH2 CLEARLY grew since KH1-- his outfit was super tiny on him, he was taller, etc. But in the beginning of KH3, Sora still looks almost the exact same as he did in KH2, so we know a whole other year didn’t pass.