This is an idea I had before the latest chapter came out, and I thought I'd post it anyways. SPOILERS for latest chapters, sort of. This is assuming that when he returned to Clow, his Sakura was seven years younger than him, which might explain her reaction.
If you think Tsubasa is mine, you're hallucinating. Besides, it's much more fun to yell at CLAMP when they delay the chapters than it would be to make it up on my own.
The two men stood facing each other, swords drawn. The taller of the two, the black haired one, grinned menacingly down at his shorter, brunette companion.
"You really think you're gonna win this one? Think again."
The shorter man just raised his sword, his amber eyes glinting in amusement and determination.
"Stalling, are you?"
They moved at the same time, lashing out with deadly blows. It was a dance, once in which a single misstep could mean injury or death. But they both knew the moves, and not one strike landed. The dance continued without pause.
Sweat dripped off a cheek; breathing was harsh and labored. Slowly, the fighters were tiring, but neither would give in.
"I'll say this, Syaoran-kun," the dark haired man panted as they exchanged blows, "you know how to use a sword."
"I could say the same for you, Touya-san." Another clash, another step; neither could gain an advantage.
Syaoran gathered his energy and launched an attack meant to end the duel. The flurry of blows pushed Touya backwards, until all he could do was block and parry. One last thrust, but before Syaoran gained the upper hand, Touya went on the offensive, pushing him back in turn.
Syaoran retreated, flipping backwards out of range, on to a nearby stone. Using the extra height to his advantage, he launched himself at his opponent. His sword was raised to stab, almost as if it was a real fight. In the moment before he knocked Touya to the ground, a frightened voice came from the castle balcony above them.
"Don't hurt Touya-kun!" Sakura shrieked.
Syaoran froze. Time seemed to slow, then to stop altogether. It was as if he was back in Tokyo, where the one he was fighting was himself. The Sakura was older, begging for him to spare the life of the one most important to her. Kurogane was there, covered in blood and holding a dying Fai protectively close.
He looked up at the little girl, and he saw her clone, the one who had died on the sword of his opponent. She was trapped, unable to leave the bubble that held all the water in Tokyo. He could see each of her tears, the desperation in her eyes, in the way she frantically clawed at the barrier. He could hear the pain in her voice, because she knew something had changed and that the Syaoran she was begging him not to kill was no longer the Syaoran that she knew and loved.
Most vivid of all was the image of the other Syaoran before him, that emotionless, uncaring gaze. All traces of humanity had left his face, and there was no expression, even as he stabbed Syaoran in the leg. That face, identical to his own, betraying the girl they both loved without a second thought.
Memories flooded over him, and he was unable to stop the recollection. Good times and bad, of his clone and that Sakura, all seen through his left eye. The happiness they had shared, the love that was the same as what he held for his Sakura. His clone's determination, and his choice to go onward. To do anything to save Sakura. The soul his clone had created, building it off the heart he was given.
Then, his own escape, and the destruction of the person his clone had become. It was his fault, all of this. Not just the deaths of Kurogane's parents and Fai's twin. He had, through his selfish, cruel wish, created and destroyed the lives of those two clones. It was the same as if he had led them to the slaughter.
And it was worse, just because she had his Sakura's face, and he was a mirror reflection. Now they were forgotten by all but him; only he remembered the sufferings they had endured, and the ultimate sacrifice both had made.
He stumbled backwards, back into reality, but his memories haunted him still. Tokyo, Infinity, Celes, Nihon, Clow. Each a world, each a price those two had paid so that he would return to his Sakura, save her. Almost unconsciously, he gripped the pendant normally hidden under his clothes. A single shard of glass, with a sakura petal trapped within, it was all that remained of them.
He missed them. He missed the Syaoran who was cheerful, without any worries or responsibilities. The Syaoran who read too much, who spent all the time he could with his princess, rather than trying to find a way to save her life. He missed the determination, the untainted strength of the clone as he searched for the feathers.
He missed that Sakura too, but thinking of her hurt much more, because it reminded him of his Sakura. The cheerfulness, the irrepressible joy. Most of all, he missed that smile, the one both Sakuras shared.
Now he had his Sakura back, and she was safe. His wish had been granted, and it left a bitter taste in his mouth. But he couldn't think that, because then his whole life had been set on the wrong path. He still loved Sakura, he still loved her more than anything in all the worlds. But some days, he wished that things could have ended differently, with two pairs of Sakuras and Syaorans, instead of just one.
Touya was staring at him strangely. "Syaoran-kun, are you alright?" He asked, concerned. Syaoran didn't respond, he merely stumbled back another step, his face pale and his breathing harsh.
"Syaoran-kun?" Touya asked again.
Syaoran shook his head, partially in response to Touya, partially in an attempt to dispel the thoughts running through his head.
"What is it, Syaoran-kun? When Sakura yelled, you freaked out. You're hand is bleeding." Syaoran looked down. The hand clutching his pendant was pouring blood. He had grabbed it so hard that the jagged edge had sliced through his palm. He shook his head again.
"Don't-" he started, then stopped.
"What?" Sakura had come running down from the balcony, and it was she who asked the question.
"Don't, ever," his eyes were vacant and worlds away, "do that again, Sakura-hime." Without another word, he turned and walked straight into the desert, his torn and battered cloak trailing behind him, a silent testament to those who were lost. Only Sakura saw the tears in his eyes as he left.
Tears made tracks in the dust on his cheeks, he stared straight ahead, not seeing even the path before him. The castle was far behind him now, and he sat on a stone at the edge of the ruins, the same place where the other Syaoran and his Sakura had sat to eat lunch when the weather was nice.
They were still here, he could feel it. Only a wish could bring them back, if they could even still return. What the other Sakura had said when she died haunted him.
"If those two keep on living, it won't end…"
"But it has ended, Sakura-chan." He spoke to the empty night sky. "And I've lost her anyway. She doesn't know me anymore, just as you didn't know your Syaoran-kun."
The world they lived in was destroyed, the people they knew gone. The only connection left was to him and their only hope of being together was through his love of his Sakura. But nothing was the same, and that relationship…
"How can you still exist if everything you ever loved is gone forever?"
I think that even after everything's resolved, even if he saves his Sakura, r!Syaoran is still going to have some majors issues. Obviously, those are reflected here. No matter how perfect everything turns out, he will always remember the choices he made, and the people who were hurt because of those choices. Wow, I'm depressing today. Hope you liked it. Why don't you review and tell me, so I don't have to wonder!