Nomura said, and it's been hinted at throughout the entirety of the series that everything has (or has the potential to grow) a heart
Exactly, I am actually surprised that there are still so many who fail to grasp that after all those hints
and it having been spilled out
clearly inside the game DDD
and by Nomura.
Xion, Naminé and Roxas have, as well as most likely Xemnas, their own hearts that were grown over the time they existed as independent entities.
Where did he say that? All i know for sure is that it has been said that nobodies can grow themselves new hearts.To be more specific i'm assuming it is only specila nobodies. It makes me wonder if they can grow and develop a heart by the end are they still nobodies. In a sense woulndt that just make them there original selves.
Anyway heart or not how would xion apperance not put sora back into a coma. What would he e made out of. She has no physcal form.
It was even said in the game DDD itself that
anything can grow a heart if the right circumstances are met, even trees, flowers and dolls.
Nomura only confirmed it again in the Ultimania interviews.
It doesn't apply only to Nobodies. The Riku Replica also had a heart and so has most likely Xion.
Why would Sora suddenly get in a coma when Xion's heart (which contains her consciousness and whole being/personality as well as
her own memories, which belong solely to her) is awakened and set free? The reason Sora couldn't awake in Days/KH 2 was because
his memories were leeched off by Xion and some of them got also into Roxas due to their connection.
Naminé spills it out to Riku in Days that the main reason that Roxas and Xion must disappear is because they carry a bunch of Sora's memories.
As we can see clearly in DDD it takes not much in order to give someone a physical form at least stable enough to walk around. This might even become a central task for Kairi, as she already helped Sora gaining a physical form back in KH 1. All this holds of course also true for Naminé and Roxas.
Seeing it from this viewpoint, Young Xehanort may after all not be totally off with calling Sora's heart a prison, as for Xion and Roxas it IS a sort of prison where their hearts are held in sleep.
---
Just to give out generally the important parts from game
and interviews here they are. Everyone pay especially attention to the things Ansem the Wise explains to Riku.
(Translations are from fellow Forum member Krexia)
Ansem the Wise said:
Ansem the Wise: It's hard to believe, that you would come here.
Riku: DiZ!? No... Ansem the Wise. Why are you here?
Ansem the Wise: Maybe I intended to atone. I know that no matter how much I apologise, I can't be forgiven. I thought if I could at least leave something behind... I turned that research of mine into data, and hid it inside Sora.
[Riku looks at the bottle in his hand.]
Riku: This is... data?
Ansem the Wise: That's right. Maybe it will be a clue for you all, to bring back your lost allies. The heart is something that can be born, and nurtured. To touch the light, to feel nature, to connect to people... the accumulation of these things gives shape to the heart. It's the same even for Nobodies who do not have hearts.
Ansem the Wise: Sora is unique; even though he returned to his own body, he allowed his Nobody to exist as it was. That is the strength of the thoughts of the people connected to his heart, the strength of his heart's connections. I dare say that even if he were to lose that heart, those he is connected to could, with just those vanished hearts and existences, bring it back.
Ansem the Wise: One's treasured things, a silent doll, trees in the forest, flowers that sway in the wind... anything has the potential to carry a heart. You don't need any special ability. That light of the heart that everyone had when they were a child - simple, honest thoughts - that is the strength of a pure heart, in which Sora believes and cannot doubt.
Ansem the Wise: If someone feels a heart there, a heart exists. Even if a heart is lost, maybe it can once again be connected. Up to this point, he has felt, accepted, and saved many hearts. And now the many hearts that sleep within Sora's heart have fallen into darkness, been stolen by darkness, sleep in darkness. The hearts dissolved in Sora -- to save them, you must act as Sora has up until now, move forward as a heart in order to succeed. His thoughts are the only way. Or to be precise, what is within them.
I bolded some crucial parts but in essence the whole speech of Ansem is pretty important as it gives a very clear view on the nature of hearts in the KH Universe.
Another bit of the stuff that includes also Xion:
Sora and Xigbar about Hearts said:
Sora: You guys, don't you have hearts? Axel, and Roxas, and Naminé -- and that girl -- in the emotions I felt from Roxas, everyone was laughing, and angry -- and sad. The tears they cried are proof of that.
Xigbar: Heh. You've finally realised.
Sora implies that Axel, Naminé, Roxas and Xion (he doesn't know her name, but it's clear he means her) have hearts, and Xigbar confirms it.
Now on to Nomura's bits about the issue in the Ultimania:
Nomura said:
— Before the ending, Riku receives research data from Ansem the Wise. In the next title, will that be the key to bringing back the people who are sleeping inside Sora?
Nomura: You could say it’s the key. That data contains the details explaining the way to connect lost hearts.
---
— It was declared from Ansem the Wise’s own mouth that everything can grow a heart.
Nomura: Yes it was, I thought I’d leave it clear in this title.
Especially the second bit spills it out flatly and on a silver platter. Nomura isn't even vague on this one but very straightforward, which is rather rare for him.
Also this one is old, from the BBS Ultimania, but there Nomura already foreshadowed heavily the stuff we got now confirmed in DDD. The only things missing are the revivals to be
actually happening and showcasing the way
how it is exactly done.
Nomura said:
-- Ansem the Wise says to Aqua “Everything is born from sleep.” What does this mean?
Nomura: In that scene the ones who are calling for “Sora” are the ones who have already disappeared from the world. But in the world of KH there is no concept of death, that for example they are just sleeping within Sora’s heart. If you can just wake them up, they’ll be able to return to the world, they would be “born from sleep”. That there would be a possibility of this, is what Ansem the Wise is saying. Even Aqua, who isn’t in the realm of light, would be born from sleep.
-- In that case, do the characters we see in that scene have a chance of returning?
Nomura: Yes. The data that Ansem has hidden within Sora is the secret to that revival. When Ansem had become DiZ, and studied the heart and emotions, the results he found he hid within Sora. There are a lot of people who thought that Coded was about finding those results, but that’s not true. The ending of Coded was about finding out that DiZ had done something to Sora, as Namine said, finding out about the data that Ansem hid. What that data is will be revealed in the next game.
I've always figured that Aqua and Terra would come to wake Ventus together. Aqua says in the Castle Oblivion scene, "Terra and I will be back to wake up before you know it". And as pretty much the only way to find Ventus' chamber in Castle Oblivion is to have Aqua lead you there, and Terra's still under MX's control (and probably will be until the very end of the Xehanort Saga), well...
I also consider Ventus one of the weakest Keyblade Wielders in the series, so in my mind, despite him being basically a being of pure light, he wouldn't be able to stand up to more than one of the 13 Darknesses. Since there are 7 Lights and 13 Darknesses, unless non-Lights join in the battle as well, that's 2 enemies for every light save the seventh. Of course, that's all just my opinion and not supported in the least by any concrete evidence.
I put Xion in the spot Ventus would have taken as I consider her a strong possibility to be a Light. She was hinted to still exist in some form during DDD, and she would probably be easier to find and save then Ven would, as nobody actually knows HOW to awaken his heart yet.
The rest of my list was decided based on Main Character Status, Keyblade Master Status, or He's Getting Trained By Yen Sid Pretty Much For This Battle Status.
Well, that's what Aqua wished to happen, it doesn't mean that it has to be that way, as the only people actually
needed to save Ventus are Sora and Aqua, and she is actually also only needed to show the way to the Chamber of Waking. The actual rescue lies in Sora's hands.
Good you pointed that out as a personal opinion, as Ventus is certainly not weak at all, it's in fact the opposite if one looks at what he, as the youngest and most handicapped one actually accomplished in BBS. Not to mention his immense speed and agility, Xion is no match for him in an actual all-outgoing fight.
I also don't see how Xion would hold out better at all against two darknesses than Ventus, Sora or Roxas could, who are all roughly at the same power level.
Xion is never even brought into play as a potential light anywhere though, there it's even more likely that Roxas might become a light, cu you know he was born partly from both Sora and Ventus, who are both lights.
Of course Xion still exists inside Sora, she may even have her own, grown heart which is already strongly hinted, but that doesn't bring her any closer into becoming a light of the X-blade at all, unlike Ventus who is already set.
The wildcards we were given by the game itself and Nomura are practically Terra (due to him possibly not being able to fill his spot until the very end), Kairi (due to the secret ending and Nomura mentioning her in the Ultimania), Roxas (due to the opening and him being depicted alongside Kairi in pictures in the Ultimania) and Lea (due to him gaining a Keyblade, although Nomura never mentions him in relation to the lights but that he wants to bring back several people and therefore seeks out the power of the Keyblade).
To say things short, except personal preference on your part obviously I don't see a trait or neccessity logic-wise why a character who is not remembered by anyone and got most of her power by leeching it off others would be chosen as a light over more obvious choices like Roxas, Ventus or Kairi.