Now the big question: How can KH be freed from this torment and restore those whose hearts have been destroyed or remain captured?

To start, let’s take a look at how DiZ’s research data plays a part. Remember, Namine said that the data stored in Sora is the key to saving everyone from torment.
Question: What was AtW’s end goal in studying the heart, what did he hope to achieve? He puts particular emphasis on solving the “mystery of the darkness of the heart” and wished to answer, “How it is born.”
Moreover, the research/experimentation we do see him conducting involves digitizing hearts (seen through his virtual Twilight Town and the attempt to encode KH).
In other words, Ansem concerned himself with both the origins of the heart and the ability to change the heart into data. Could the reverse then be said to be true? Could DiZ have been trying to convert hearts into data so that he could also make hearts [i]out[/i] of data?
Logically, it entails that the end result would be that AtW were capable of [i]creating[/i] a heart, which Xehanort had actually hinted at in the Ansem Reports:
“This may be a step toward creating a heart from nothing.”
That’s what he sought. To understand the workings of the heart is epitomized in making one. AtW wanted to play God in the KH universe (granted, not out of selfish intent, but in the name of science and benefitting the health of his people), to be able to create a heart outside of Kingdom Hearts.

Recall that while Ansem thought it best to stop the research for ethical reasons, he later continued it (post-ban to the realm of Nothing) in order to study the Heartless/Nobodies. At this time he must have also discovered what I had mentioned in the op: That the emotions disappear and must accumulate in Kingdom Hearts (otherwise, how else would he know about the torment?).

This problem prompted him to continue his efforts to create a fully functioning heart, as that is the only way the torment can be relieved.
But did he succeed?
Nope. Not quite.
As DiZ said:
[quote][b]The process of encoding hearts is incalculable.[/b] The inhabitants of my Twilight Town were data created from real hearts. I was convinced that they would think and behave the way I had envisioned - -but I couldn't have been more wrong.[b] A heart is so much more than any system.[/b] I saw it when Roxas and Kairi crossed paths. I knew. But I was too stubborn to accept it. It's always the same. I try to wrap my mind around things my heart already knows, only to fail. While I was trying to bring Sora back, I had so many plans in store. But once Sora was an acting force, they fell apart.[b] All my research amounted to nothing, compared with that one boy's heart.[/b][/quote]

It is possible to make a digitized heart, yes, but making a real heart out of it is beyond the power of the scientist. Still... note what he says about Sora. All of his research amounted to nothing (note: if this is really ALL his research, it also includes the data he inserted into Sora!), compared with Sora’s heart. There’s something about Sora’s heart, then, that, by placing the data into Sora, can help it realize its potential.

In addition to knowing about torment, it appears, based on dialogue of the secret ending, that AtW also is aware of the special bond between Sora and Ven. Undoubtedly, he discovered this via Namine. Now that we know Roxas had Ven’s heart in him, there’s no way DiZ wasn’t aware of it. Namine told DiZ about the tormented memories that rested within Sora, and DiZ could see that Roxas resembled Ven.

While Roxas was in the data TT, then, DiZ decided to put his research to use.
Ansem placed the culmination of his research into Sora, data which could complete Ven’s heart.

AtW hoped that because of Sora’s uncanny ability to connect his heart to those in torment, he could somehow find a way to make the data become real.
While you may shrug this off as impossible, it’s already been done. See: Data Sora. His keyblade was digital and even broken by Malerficent. But by bonding with his friends, it created a legitimate keyblade. We might even speculate, then, that Data Sora’s heart was real too.

The exact details of how Sora will get the data to be converted into a real heart is a bit hazy, but suffice it to say, you know he’ll find a way.
And when that happens, I propose that Ven’s heart will still be in a state of pure light. That is, the data DiZ inserted cannot be made of darkness.
The reason I say this is because of preexisting examples we have of restoring a destroyed heart. Kairi’s light essentially rejuvenated Sora’s heart. Sora did this with Ven as well, albeit only with a fraction of his heart. And even though Ven’s heart was devoid of darkness, Sora still filled in the remainder with light, so darkness is not a necessity in this case. Since the heart is [i]inherently[/i] light, you need light to complete it.

 So with someone else’s pure heart resting within him, Sora’s gotta find a way to get it out. This certainly sounds familiar...
Well, how’d he get Kairi’s heart out? By stabbing himself!
Granted, since BbS showed us that the Heart Unlocker isn’t the only keyblade that can release a heart, I doubt he would have to create it all over again (which would be odd considering he’d have to take the princesses hearts...).

On a small tangent, to all of those who reject the idea of Sora sacrificing himself yet again, I point to Roxas and Riku’s foreshadowing in coded. They say, quite a few times actually, that the darkness produced by torment might consume Sora.

[quote] No matter what happens, you never change.
  I wanted you to understand that.
  Pretty soon, you're going to learn a lot of truths.
  Forgetting important things, losing them... Being deceived...
  [b]You might fall into Torment so deep that you lose yourself.[/b]
  But Sora, you'll be fine.
  No matter what happens, you can handle the pain. You can accept and overcome
  it. ...You can heal it.
[/quote]

[quote]Do you understand, Sora?
  You are caught up in your own pain.
  This pain, this torment, cannot be healed.
  It will only get worse from now on.
  [b]Ultimately, it will pull your heart into the darkness![/b]
[/quote]

[quote][b]If you remain obsessed with your lost memories, the torment will worsen,
  and you will surely fall into the darkness...
[/b][/quote]

[quote]When I leave the card room, I forget everything I did, and everybody I met...
  But then I realize I forgot them, and feel sad.
  [b]That sadness is tormenting me, and pulling my heart into the Darkness...[/b]
  What am I supposed to do?
[/quote]

[quote]  Pain, is it.
  I thought I told you.
  [b]If you obsess over your torment, it will someday pull your heart into the
  Darkness.[/b] All you can do is erase all the pain
[/quote]

Sounds to me inevitable.
Sora has an uncanny ability to connect his heart to those in torment. That has accrued undoubtedly a large amount of darkness within his heart, and if he were to release Ven’s heart, the darkness of that torment would consume him... maybe.

How he goes about it, as I said, doesn’t have to be through the Heart Unlocker. As MX says in the Xehanort Reports, a wielder with the power of a Master has the ability to release hearts from their vessel. So... Sora has to become a master (or find one, though I’m more apt to believe he’ll become one first). Upon attaining that power, Sora can use the KK to release Ven’s heart.

But where does that leave him? He’s going to be consumed by darkness and go through the whole Nobody ordeal again, right?
Not necessarily.

Let me introduce how I think this can all be resolved.
Since the heart’s darkness still exists (as the Heartless), you need light to bring back a complete heart and free the crippled beings from their torment, as I’ve already said. And if we’re talking about this on a large scale, with thousands, or perhaps millions who need their light back, then what better to bring it back than Kingdom Hearts, the source of all light.

Throughout the series, Xehanort and his incarnations have had one main goal (though the ulterior motives were entirely different): to control Kingdom Hearts. While this can obviously be considered a very selfish act, who’s to say the protagonists can’t use it for good?

So if Sora’s the only one who can not only heal the pain of those connected to him, but to all of those in torment, he’s going to have to control Kingdom Hearts. How?
Easy, the X-Blade.
We’ve got Ven, restored with pure light. So who’s the darkness?
The problem is, it seems as though darkness has the upper hand in the case of the X-Blade. Why did Vanitas get the X-Blade when technically, the two were equal in power and one being? Why couldn’t Ven have used the X-Blade when they fused? Because of the invasive nature of darkness, of course, it seeks to dominate the light, but the light does not do so in return. Hence it acquires the power that is created when they collide.

We have a big problem, then. Even if Ven’s heart could intersect with a heart of pure darkness, the X-Blade would end up in their hands.
Remember, though, darkness isn’t necessarily bad.

Sora’s heart is already connected to Ven’s.
And when Sora releases Ven’s heart, his heart will be consumed by darkness.
That’s what Sora needs to do. To steal a quote from Riku, “be the darkness.”
But it wouldn’t work if he became a Heartless. He needs to become darkness without losing himself to it, to become, in essence, a “good” darkness. If he was one of only two people capable of retaining his sense of self as a Heartless, he must now take it a step further and retain his sense of self, his complete being, as someone with a heart of absolute darkness.

For this reason, on Sora’s journey, he must learn to cultivate and control his darkness (the one we’ve seen through Anti form), in addition to becoming a master and finding a way to make the heart data real.

So we skip ahead. Sora is successful, he becomes darkness, his heart crosses with Ven’s (note: they don’t have to fuse to have “intersecting” hearts), out comes the X-Blade, here comes KH. Together, Sora and Ventus use the X-Blade to “open the door” (as they both said they would) and “save those crippled beings.”

There is yet another problem, though! This is what MX had [i]wanted[/i]. The worlds are going to be destroyed if the door stays open, and a new age of Darkness and Keyblade War II (lawl) will commence. The torment will pour out, true, but the emotions still have no hearts which they can go to. [this portion was cut out and is answered in my response to Radon]. Not to mention, Sora is still absolute darkness. What a mess! What can be done?

Take it a step further. Don’t just open up Kingdom Hearts, become Kingdom Hearts. How?
Here’s a curve ball for you: What happens when you stab yourself with the X-Blade?
The X-Blade “is one together with the existence called Kingdom Hearts” as MX said, unlike the Keyblades. The door of KH is no longer sealed thanks to the X-Blade. By unlocking your own heart with the X-Blade, your heart could become and control Kingdom Hearts.

And that’s what Sora does.
Why Sora, though?
Because his heart can open the Door to Light.
As Kingdom Hearts, he could revive the destroyed hearts, open the Door to Light, and allow hearts to flood through the door to merge with their emotions. This is a critical time though because Sora will be feeling the torment of virtually all of those lost to the darkness, and a pain that large could swallow the heart in darkness. In this case, that would effectively destroy Kingdom Hearts. But we know that won’t happen.

And with Sora gone, the X-Blade would disappear too. There would be no more threat to the worlds. Unfortunately, they’ll find a way to bring him back since the series won’t be ending with KH3.

AND THAT'S MY FANFIC, HOEP U ALL ENJOYED IT THE END.

[QUOTE=Radon;4963697]So wait, according to your theory is it possible that LS could be one of these torment enemies?[/QUOTE]

It's related to torment at least. The Lingering Sentiment (I believe), is the result of an exceptionally strong emotion, more so than most who lose their heart. It clings on to a physical object (usually associated with the person who was lost to the darkness) as a lasting imprint of that emotion. Whereas Unversed use darkness to manifest, the LS use actual objects. So it's basically
Organization XIII is to Normal Nobodies as Lingering Sentiment is to Unversed.

[QUOTE=Insomniac;4964460]These questions are not ment to offend you and they are not an attempt to "prove you wrong" in any way and I apologize if they appear that way.[/QUOTE]

I hope they are an attempt to prove me wrong, that wouldn't offend me. A theory should be able to survive public scrutiny, so don't apologize for posing a legitimate question.

[QUOTE=Zulkir;4963995]Hmm, what knowledge do we have that the heart is destroyed upon becoming a pureblood?

The only pureblood who gave us perspective was Sora, who simply described it as falling forever.[/quote]

Really, I'm just basing it on the fact that no heart is released (and this is supposed to be significant). If portions of the heart can be destroyed (as is the case with Vanitas), then, yeah.
Sora is a special case, as he retained a sense of self (not on the level of Xehanort, but it was still there). Even as a Heartless, he still traveled to Kairi and would not harm her.



[QUOTE=Zulkir;4963995]
However, the heart still isn't destroyed, as Mickey explained in the FM1 cutscene "This is the other side, where stolen hearts are gathered".
[/QUOTE]
Truthfully, this theory can still work with the idea that the heart isn't destroyed, and it's what I believed prior to BbS. That instead of being destroyed, the heart is brought to the Dark Realm (you'll notice that I say the emotions are brought there, sans their hearts, and that’s really what I’m basing it on). Instead of recreating the hearts, then, it would simply be a matter of releasing them from Kingdom Hearts, so it'd need a few tweaks.

I just think the idea of them being destroyed is more potent, to be honest and makes more sense when I visualize the process. Really not much more to it, though I’m open to the idea of them being in the Dark Realm.

It's hard to say what exactly Mickey means by "stolen heart" here. Riku is a stolen heart, so that's why he's there, and yet he's clearly fending off the darkness, so what would happen to him if he gave in (so would a stolen heart even be capable of "living" in the dark realm)? Would he be consumed/destroyed? Hearts taken by the Emblems are also classified as being "stolen hearts," yet they clearly don't end up in the Realm of Darkness.
And then there's the word "gather." Hearts gathering. Sounds like Kingdom Hearts. So is he suggesting instead that the stolen hearts go to KH, as opposed to wandering around the Dark Realm?
That may be the case, and if it is, then, as I said, it can still work with my theory.

Instead of destroying the hearts, the purebloods cause the hearts to return to KH, with their torment. It builds up, Sora needs to release the torment, they open KH with the X-Blade, the hearts come out with their torment (and in this case, they'd become Heartless, like in the case where Xemnas' KH exploded), Sora becomes one with KH, restores the beings, brings them to the realm of light.