A/N: Hope you all had a good Christmas! Thanks to all those who sent me messages (and the review too!) making the guesses - I nicked a few ideas and went with a slightly different path to the one I'd originally planned.
Unknown
It had been black for as long as he could remember now. Black, except for the one small patch of white around him. His Heart.
Of course, it wasn't entirely his. It hadn't been for some time. Not since it had been stolen, forcing a part of him to take a life elsewhere as the Lingering Sentiment.
But now, things had changed. There were many patches of white here now, each with a figure lying apparently unconscious on them. They stretched on as far as he could see around him.
Each one was a Heart and it's owner – or a part of them, at least. Only one seemed to be missing it's owner, and that patch seemed to flicker and distort, as if something were trying to gain a hold over it.
He watched impassively. It had nothing to do with him. He would have fought to gain his own Heart back, but without a form to contain it it would just be lost again.
The Heart without the owner solidified, becoming as the rest, then it's owner seemed to drop down onto it.
This was something to do with him now.
"Ven?" he murmured in a voice not heard for many years. "Is that you?"
The owner, of course, did not respond.
Taking a risk, he took to his feet and started leaping from Heart to Heart until he reached the young boy that owned the Heart, and seemed so familiar to him.
It was not who he thought it was, but there were similarities, and the faint hint of familiarity, as if he'd seen this boy before.
The boy stirred. He stepped back so he wouldn't be seen, watching the boy get to his feet and look around.
"I guess these must be all the Hearts that make him up," he said in a voice that also seemed familiar, not noticing the company behind him. "I'll save you all. I'll get you all back where you belong."
"It's not that easy," he told this newcomer, speaking aloud to him at last.
"Huh? Who're you?" he asked, turning quickly.
"Another trapped here just like you. My Heart is over there," he pointed. There was a thin and faint white line from his patch that followed the route here, and connected him to it around his waist like a belt.
"Yeah, but who are you?"
"Terra, a Keyblade Master in training... or I was, at least."
"What happened to you?"
"He took advantage of my tapping the darkness and possessed me."
"He? You mean Xemnas?"
"Xemnas? No, he called himself Xehanort. Anyway, who are you?"
"I'm Sora, Keyblade Master, wielder of the Keyblade of the realm of Light, and Grandmaster of the Dark Arcology." He made a face, "I hate titles. They make me sound like I think I'm too important."
"You certainly sound it. You remind me of someone I know... or knew... Ventus."
"Ventus," Sora echoed, frowning. "It's familiar... I know the name from somewhere." He started pacing around, then stopped and said, "I remember! When I was a kid, I met him... well, not him, but his Heart. He said it needed a place to stay, so I let him stay in my own Heart."
"I don't suppose I could talk..." he trailed off.
Sora shook his head, "I wouldn't know how. I think it's up to him anyway."
Terra let it go, staring out over the collected Hearts again. "You sounded like you know these people."
"Yeah. They belong to my Arcology. Vexen used the Kingdom Heart that powers it to steal all their Hearts – even mine."
"But you only just got here. Your Heart was here before you."
"I know. I got turned into a Nobody. I still exist out there, but without a Heart. I guess I'm the bit of me still with my Heart."
"You think your body is still out there?"
"I certainly hope so. It was a key part to the plan."
"Plan?"
"Yeah, to get rid of him again. He'll think he's destroying what's left of me there, but if things to go plan, it'll just be a trick."
"You plan to go back then."
"Sure do. Can't beat him if I'm stuck in here, right?"
"If I could reach my own body, I could help."
"You've got yours still?"
"It's in a place called the Keyblade Graveyard. Looks like a big suit of armour."
"Hey, I know that thing! I've fought it before once. It mistook me for my friend Riku."
"That's my body. It's got all of me that isn't here." Sora's eyes grew thoughtful. "What?"
"I think you can help. I've got another plan." He turned to the empty air and shouted, "Roxas!"
"Sora?" a voice came back. Like Sora's voice, it sounded similar to Ventus. "Is that you?"
"No, it's Xemnas pretending," he answered tartly. "Honestly, who else has a link to you?"
"Stupid question I guess."
"I need you to do something for me."
Core of the Arcology
The Lingering Sentiment, kept hidden on the platform by a carefully crafted illusion from Zexion, remained motionless except to stare emptily at Xemnas attempting to destroy Sora.
Roxas seemed to listen for a few moments, then laid a hand on one shoulder. A light began to spread outwards from it. As it passed, the armour seemed to give way to a living person again, wearing a robe matching Xemnas' one.
The helmet was the last to be replaced, leaving a calm but harsh face framed by somewhat messy dark hair.
"Well what do you know," he murmured. "Sora was right. I'll take it from here," he told Zexion and Roxas, striding from the illusion, then he too vanished. Roxas glanced at Zexion, who shrugged then turned back to the struggle just in time to see Sora begin to fade away.
"Oh bugger," Roxas murmured. "I hope he meant for that to happen."
Zexion flashed him a mysterious smile.
Down below, Xemnas began to laugh as he summoned and kept Sora's keyblade. He was stopped only by something sending him smashing into the ground.
Xemnas got up, returned to the air and searched, but was struck down again. There followed a brief conversation with a whispered voice, then the person that had come from the Lingering Sentiment reappeared, also hanging in mid air. He pushed back the hood of his robe. Mickey let out a surprised gasp.
"You!" Xemnas snarled.
"It's been a long time, Xehanort. Think you can beat me again?" A keyblade appeared in his own hand, an earthy brown with a long blade and a blue handle.
"How did you escape the darkness, Terra?"
"I had help from a new friend. I believe you know him – Sora."
"Sora!" he half screamed. "I hate you, Sora!"
Roxas could have sworn he heard Sora's voice murmur, "At last."
Enraged now, Xemnas rose up to the same level as Terra and swung Sora's Keyblade wildly. Terra coolly blocked without even a change in expression, which seemed to anger Xemnas even more. He seemed to go almost berserk with his attacks, screaming half-formed insults at both Terra and Sora.
Roxas glanced to the others here. Vexen looked uncertain, as if he couldn't decide who he wanted to win. His new Heart, and with it feelings, seemed to have torn his loyalties. He'd helped in their fight against Xemnas, but had hardly contributed much.
Zexion was watching with interest. Every once in a while, his eyes would flick to another part of the Core and back. Roxas saw nothing there, leaving him wondering curiously what it was he'd seen.
Goofy had now joined Donald with Jamie and Alex. It was anyone's guess what they were discussing.
Mickey had been with them, but left them quickly when he'd seen Terra. Star Seeker, his own keyblade, seemed to twitch in his hand as if he wanted to get involved too. Something clearly held him back though.
Then there was Riku and Kairi. Kairi hadn't looked back down yet, still practically stuck to Riku, who knelt with her watching. There was no mistaking that look, if it hadn't been for Kairi, he'd have been after a piece of Xemnas in a flash.
"Not watching the amusements?" Axel asked quietly, coming up beside him.
"They're hardly amusements. Sora's gone, and now some newcomer is taking a pounding from Xemnas."
"So you don't see anything out of the ordinary, besides those two?"
"No, why?"
Axel led him to the top of the stairs down, where the platform gave way to allow people to go down them.
"Look over in the corner opposite us," he pointed.
Roxas peered down, seeing nothing at first.
Then he realized what Axel had been pointing at, and laughed.
"I should have known there was a reason he looked so confident."
"Don't spoil it for the others. I want to see how they react when they find out."
Terra stumbled back on the air after a particularly strong strike. He was breathing hard now, but refused to give up. Xemnas struck twice more, on the second strike not only disarming him but taking his Keyblade.
"Alright now," Roxas heard Sora's voice murmur again. "Let's finish this."
Terra seemed to nod in answer to this, and dropped to a piece of stair in the corner underneath where Roxas stood.
"What's wrong – afraid?" Xemnas taunted.
"Of you? Never. Of him?" he looked over to the opposing corner. "Anyone with sense should be."
"I'm not falling for that trick."
"Shame," Sora called to him from the corner. "He's right." Kairi looked up when she heard his voice, then looked down.
Xemnas also turned to see Sora leaning in the corner. He looked exactly the same as he had before being destroyed, except he was a ghostly transparent.
"I'll take that," he told Xemnas, his keyblade returning to him. Where his ghostly hand took hold of it, he seemed to become real again, an effect that spread until he was fully solid.
"But I destroyed you!"
"I'm terribly sorry," he said theatrically, "But that wasn't really me. I tricked you again."
Xemnas dived at him, but Sora vanished before he got there, leaving him to slam into a wall. He reappeared on the platform nearby.
"Your Majesty, would you lend me the Kingdom Key from the realm of Darkness?"
"Of course, Sora," he answered, handing it over. "But what for?"
"To finish this, of course," he told Mickey. He headed to the stairs with both Kingdom Keys in hand, and walked off where the stairs stopped into mid air.
Xemnas had apparently recovered, meeting him.
"You will not escape me again," he growled.
"That's right. You know why? Because this is my Arcology, and it's residents are as much my friends as Riku, or Kairi, or King Mickey. I fight for my friends when they can't, and I'll save them when they need me most. Right now, they need me, and they can't fight. I'm going to defeat you again, and return all those Hearts back to their rightful owners – and then, you'll be left without a Heart again, because I've given Terra his back as well. All you'll have left is yourself. You don't have any friends, you don't have any allies. You'll be alone, with no one left who cares about you."
Xemnas gave a disjointed, deranged howl and went even more wild than he had before. Despite everything he had, Sora remained unmoved, simply blocking everything with one of the two Kingdom Keys with barely any effort at all.
For the third time, Xemnas did battle against him, becoming increasingly more frustrated and frantic. When Sora took a swipe and knocked Terra's keyblade back to it's owner, he simply recreated the ethereal blades and resumed his attack.
This was what he'd been waiting for. Now he stopped playing the defensive, and went all-out on him. The Kingdom Heart above returned slowly to it's normal white colour now as he fought, and it's beat increased to match the steady, measured strikes Sora was making, emphasising every other blow.
The twin Kingdom Keys glowed, one light, one dark. As the glows intensified, they seemed to harm Xemnas more and more. Finally he drew away from Sora, keeping his distance.
"No... this cannot be! I embody nothing... light and dark together... you cannot defeat me!"
"Light and dark together," Sora repeated holding up the Kingdom Keys. "You don't think I borrowed this one for nothing, do you?"
"It makes... no difference..."
"Oh, but it does. I realised one Kingdom Key wasn't going to defeat you. That's why you were able to create the link and come back. Riku has one of the keyblades from the realm of Darkness, but he didn't have the Kingdom Key from there, still allowing you. But with these two... you embody nothing, but these are the weapon against it."
"They're incomplete that way," Xemnas told him. "They can't be used until completed, and until completed, you'll never defeat me."
"Oh yeah?"
Sora crossed the Keyblades together. Their glows merged and encapsulated both of them. When it cleared, a single blade remained, the two Kingdom Keys fused together. From that point outwards was the blade of a sword, and on either side of the point of fusion green teeth faced outwards. The handles of the blade were also merged, Sora's hands on either side.
High above, the Kingdom Heart rid itself of the last of it's darkness, full and white once more. It went unnoticed in the light of the creation of this new blade.
"The legendary blade," he heard Mickey tell the others from above.
"Impossible," Xemnas breathed. "You can't do it alone. It needs one of light and one of dark."
"I maintain a link to Roxas," Sora told him. "There's nothing that says we need to be combined to do it. He's as much a part of me as I am of him, even separated like this."
"You wouldn't... it's too dangerous to keep around."
"I know... but do you know what it means, Xemnas?"
"The χ-blade... 'χ'... an ancient letter. Some say 'kye,' but the meaning is the same. Death... A letter that spells endings." He then looked surprised at himself. "How do I know this? Why do I know about it?"
"You may never know," Sora told him. "Guess who's end it is now, Xemnas? Or would you prefer Xehanort?"
Xemnas either couldn't or wouldn't react, watching swing of the great blade grow closer. All the Hearts within him gave him feelings, and his face showed the fear and horror he had because of it. Not the fear and horror of one Heart, but that of many.
The blade made a clean cut, though it seemed to leave no damage. Xemnas reached out imploringly to Sora, who still held the blade in both hands, but Sora made no move to aid him.
He seemed to expand, growing larger until he exploded into a mass of many small white lights floating around the room. Some were larger than others, some winked other colours. They were innumerable, bathing all in their soft lights as they left through the walls.
"What are they?" Kairi asked in wonderment.
"Hearts," Roxas told her. "Returning to their Nobodies."
It took some time for them to clear, and not a single one of them moved during that time.
Eventually only two were left, hovering in front of Sora.
"It looks like you've done it again, Sora," a voice seemed to come from one of them.
"Who... wait. Ventus, right?"
"You remember! I've been watching. Of course, I can't do much else. I just wanted to tell you something before I rejoined you again."
"What's that?"
"Terra. Tell him... tell him I forgive him."
"What for?"
"He did something not unlike your friend Riku. Your forgiving him proved I can do the same for Terra."
"I'll tell him."
"Thank you, Sora."
Ventus rejoined Sora's own Heart, which in turn returned to him.
"Now to do something about the Arcology and it's Heart," Sora murmured to himself.