@GiverOfThePeace, @Axl233: The stars we see in The Final World all seem to have in common that they have something connecting them to the world.
Video about all The Final World Stars dialogues:
https://www.youtube.com/watch?v=atd0dgRkl2k
All The Final World cutscenes:
https://www.youtube.com/watch?v=atd0dgRkl2k (Which may be missing some Stars dialogue.)
Lemme amass some dialogue about his situation:
- Chirithy tells Sora "There's nothing else beyond this. You've wandered here more than once on your visits to the Station of Awakening, buuut... I let that slide. The edges of sleep and death touch, and one can't help the occasional crossover."
- Chirithy later states these others times were by Sora's own choice & this time is very different, stating Sora will need to piece himself together in this world, clarifying he's "conceptually scattered" but "on the outside, you're just fine".
- Chirity answers about death as: "The natural end for those whose hearts and bodies perish together. But some persist, and arrive here." and later says "Usually, only a heart can reach the final world. But since you've clearly managed to retain some kind of form, that can only mean your body was cast into this world as well."
- When it's time for Sora to leave, Chirithy answers Sora's sarcastic thanks with "What? I'm doing you a big favor, you know. Don't push it."
- When Sora asks Chirithy "What about my friends?", Chirithy says "I'm afraid that no one else arrived with you." So we have good reason to believe Sora's friends didn't put themselves back together. Chirithy adds "And if they're not here, they're either gone forever, or they're clinging to the world you came from."
So Sora's state of his body being in The Final World to reassemble definitely seems like the exception, not the norm.
- Curiously, when Sora tells Chirithy "You still look like you" & offers to help find Chirithy's pieces, Chirithy says "Oh, I don't work like that.". So apparently, Chirithy will not get conceptually scattered? Or not go to The Final World as just a heart?
Anyway, Sora leaves, & asking Chirithy, Sora decides to try the Power of Waking to restore his friends' hearts, saying it'll take all his heart.
I think that, given that we see Sora rescue his friends' Hearts from a Heartless, & see the Hearts leave, we can assume his friends were clinging to the world, & their Hearts came back, after being seized by darkness.
- Namine: "I'm so glad that you managed to hold onto who you are." Namine also says about Kairi, to Sora: "She's fighting with all her strength to keep you from fading away."
- Sora: "So the reason I retained my form in this place..." Namine: "It's because she's holding you together. Go to her."
Chirithy also hints at this earlier, telling Sora he's "hanging on by a thread".
So yeah, him coming back this way is VERY dependent on Kairi.
The good news is Namine tells Sora she was in Kairi's heart, and struck down by a powerful darkness, then found herself there. Presumably, this is the Demon Tide, since that's what took Kairi.
What this means is Kairi, when "fighting with all her strength", can facilitate this kind of resurrection for Sora.
But presumably, Kairi wasn't struck down by a keyblade, nor were most of the other stars. Nor Sora. He was being exposed to the darkness slipping past Riku from the Demon Tide when he went down. Doesn't seem like a Keyblade induced death.
In fact, rewatching the cutscene, the Demon Tide gets Aqua, Ventus, Kairi, Axel, Mickey, Donald, Goofy, & then Riku & Sora, then we're told that Darkness prevailed and Light expired.
Many of the stars talk about their feelings, memories, thoughts, etc. So they aren't entirely gone. And the 2nd voiced star is capable of moving & speaking. I'd argue they have some physicality. Doesn't seem like a product of a Keyblade either, given Sora didn't even seem to die to a Keyblade but to the Demon Tide.
(Sorry about all the words.)