Here's my theory, if anyone cares to take time to read it.
I know its long, but its sort of a compilation of theories w/explanations. I don't know where to post it so it can be viewed by the rep w/all the oter theories to be sonsidered.
Sunset Horizons and Birth by Sleep
I think that the FS and BHS are new because Nomura said they weren't people we know, just connected in some way to people we know. Maybe the brown haired guy is Xehanort before he lost his memories and some weird event turned his hair white. Either that or he’s a brand new character, or related to Sora. Then again, the BHS could be related to Sora because he looks so much like Roxas, and Roxas and Sora look like they could be related because they are created from the same being. This would just mean Sora got his brown hair from his mother’s side or something. Nomura did say this was a prequel, so maybe the Mickey shown is one from the past or the present gone to the past and the other soldier characters are either the original or one of the first few keyblade wielders and the purpose of showing them is to start a new series to explain the origin of the keyblades, heartless, nobodies, the door to the light, and all other enigmatic Kingdom Hearts terms. The Mickey in the end of Birth by sleep has a different keyblade, which is why I think he is a different Mickey from the past. They all look the same after all, and the King Mickey of Sora’s time got his keyblade from the world of darkness while stuck inside and searching kingdom hearts, but the King Mickey in this video has a magic based keyblade (there’s probably a very good reason for this since the elder mage, EM, uses a lot of magic and this keyblade would be a good match for him). The reason the current Mickey didn’t know of this is because the records were buried and hidden, just as the Japanese characters say that the truth of this event was hidden. Maybe King Mickey found the truth behind these events at the end of KH2 and that is what the letter to Sora is about in the end, and now they will have to solve the mystery of the past and save the future (door to light & Kingdom hearts) in the next installment that takes place in Sora’s time, but before that Nomura must show us the prequel in his new series.
The lost two could be the other two characters who die or are "lost" in some way after this battle, or they could represent the bad guys who are "lost" because they're evil, although the heartless thing seems to have been created by the bad old guy. Chasers could be a new name for either the bad guys or the goods for this new thing, and Xehanort's memories the key, and what we're seeing, also part of the keyblade wars. Master of the keyblade could have been a reason for the war to determine, or he was a participant. Birth by sleep obviously deals with the Xemnas room with the armored remains which seem in need of awakening, which is what the awakening room Xemnas is searching for is for.
The odd thing is Sora fights the strongest one, the brown haired one, which you can tell by his stature and helmet. I think the path Sora takes is into the past, just like him going into the past to see the building of Mickey's castle and save the corner stone of light (black and white world). Another possible reason for Xehanort change in hair color could be that something happens to him. This would also explain the change in his name to resemble a nobody and a person of importance regarding kingdom hearts (anyone/no heart + X). Maybe he gave up his memories for some reason, or did some sort of sacrifice to save the world cause him to lose his heart and memories and then be reformed into a new person far away.
Someone else suggested that the ES somehow merged with the UEM. This makes sense to me because it could explain the change in hair color among other things. Maybe the ES fights the UEM and the UEM is about to die, so he somehow puts a piece of himself into the ES and a completely new person is made with a new heart. The trouble is this would not explain why the ES still exists and why he tells Sora that he despises Xehanort if he is the body that creates Xehanort according to this theory. Maybe Xehanort is the nobody of the ES through similar sacrificial means that Sora went through which would leave the body of the ES intact. This could make the role of the FS similar to Kairi’s role when she saved Sora. The heart of the UEM could have inhabited this nobody. This would allow for Xehanort a heart and therefore a nobody for himself later on and it would also explain why Xehanort’s heartless looks a lot like the EM and why Xehanort’s unknown looks more like Xehanort. This makes the most sense, but his very hard to understand and explain.
This is similar to the theory that Xehanort is a nobody to the brown haired armored knight in the same way Roxas is a nobody to Sora. I believe that Roxas did have a heart, but he only had a heart through Sora, in a sense (the other side of his heart), and this is why Sora felt nostalgic in Twilight Town. I believe the case with Xehanort is similar, (except maybe his nobody somehow took on the heart of the EM as he was dying as well) which would make him able to have a nobody (Xemnas). The connections are there; both forgot their original selves, and both of their somebody was still whole again after they were created. This would also match his nobody name of either another + X or no heart + X. When Xehanort abandoned his connection to his heart, a nobody and a heartless were created in the process. This would also explain why Xehanort’s heartless was the only kind in human form and so strong (extenuating circumstances screwing up the usual process just like with the Namine and Kairi situation). Not to mention the fact that the heart of the original somebody (ES) is very strong. I hold to this theory the most because it has the fewest discrepancies.
Either way, the door to the light must eventually be explained, and I believe the ultimate goal is to find the original pure light that is supposedly in kingdom hearts or in the door to the light itself. I believe this should bring about the re connection of all the worlds in peace just like Kairi’s grandmother said. They fought over the original light in the beginning and split. It should be the keyblade master’s goal to rejoin the worlds, which would put an end to the heartless. This would explain Sora’s connection to the door to the light as a keyblade master of the keyblade from the world of the light. The enigmatic voice of the first game did say he would open the door to the light, and he hasn’t “REALLY” done this yet. I keep thinking Sora is so special (The great hero).
Chick has dark world keyblade.
Blonde has twilight keyblade.
Brown big guy has light world keyblade.
I wonder if we’re ever going to see the parents of these three and witness their worry and confusion as to where their children have been…or do they already know and therefore have no reason to worry. I mean we know at least Sora has a mother, even if he may have been adopted, we don’t know. Kair’s a princess; she should so try to find her parents on Radiant Gardens! Maybe Nomura Believes they would get in the way of the story or are not needed for it at all. We haven’t even seen their faces, and Kairi never talked about being asked by Sora’s or Riku’s parents where they were.
Anyways, that's enough for my theories. It would be tragic if Xehanort was originally the ultimate good guy and became the ultimate bad guy (in a sense it was him, TWICE in two forms). That would mean all this time he's been looking for the memories of his lost somebody because he's been trying to regain his heart. Although Xehanort probably wasn't even his original form's name before he lost his memories because this name can be jumbled up to be no heart or another without the X. The old friend could be his former fighting buddy in a past life, or even his former self (doubt it by the size of the armor shown though) And by the way, the blond haired guy wasn't dead yet, his eyes still moved a little, and the only thing that broke off on his fall down was his key and his helmet. He still has a small chance to live. It looked like those two characters had the hots for each other when he was about to be frozen, and when he was in the girls arms.
Seriously, that is enough with more of my theorizing. I hate waiting, especially since I know it will be a long while. I really hope KHII FM+ and Re:Com come to America! I hope this is a movie or something too since it's not going to be called KHIII. It will be a while before I get a PS3, and I don't want to wait long after something new comes out. I love that it's probably a prequel, but that means no Sora !!!
*tear* *tear*… yet another reason why I hope it's a movie. I fear I will be too busy and grow out of video games by the time something new comes out!
This better not become an extended series like final fantasy. I’ll be way too old before I can learn all the secrets behind Kingdom Hearts and I’ll become disinterested! Nomura said this wouldn’t happen, and I hope he doesn’t change his mind. He better end it with this new project and KHIII (I hope).
Now that I think about it more, a new series would be fun, and this is what Nomura seems to have in mind, but it would most likely be a prequel series ending with Sora and his final journey to save the universe and gain back the original light that Kairi's mother talked about. I really believe he'll end with Sora because I think he has grown attached to Sora as the ultimate hero in the end. Heck, he even has his ES complimenting the strength in Sora's heart after you defeat him (albeit a rather obscure compliment). I would love to see a prequel series explaining the origin of heartless, nobodies, kingdom hearts itslef, the door to the light, and everything else that is unexplained, but I hope it will end (eventually) with Sora and the adventure dealing with the letter he received and also him finally opening the door to the light for the sake of the whole worlds.
