Title: Keystone
Rating: PG
Warnings: Some blood; spoilers for Ceres arc.
Summary: Written for the "reverse fic" challenge to swap Kurogane and Fai's role in a scene in the manga. I just couldn't let the challenge go by without SOMEONE doing that particular scene in Ceres.

The floor and walls of the palace writhed and twisted, lashed by the deadly moire patterns of the collapsing magic. They wrapped in shifting spirals, with the center fixed on the dead king's body - and on Kurogane.

"What's happening?" he demanded, grabbing Fai's arm and shaking him out of his daze.

Slowly, Fai raised his face, his expression dull and frozen. "Ashura was the keystone," he whispered; Kurogane had to strain to hear him over the distant rumble of collapsing masonry. "The binding force that held this world together. Without him - without him, it will collapse... and center upon the one who killed him."

"And you didn't think to tell us this earlier?" Kurogane yelped.

The look Fai shot him seared him with grief and reproach. "I meant to keep my promise," Fai said in a shaking voice. "I was going to kill King Ashura, and then die with him. I never meant for you to..."

"There's no time for this now!" Still holding the sleeve of Fai's coat, Kurogane dragged him to his feet, looking around to locate the others. "We've got to get out of here. Mokona! "

"It's too late," Fai said, his voice tired and numb. As he spoke, the palace chamber rocked as though in an earthquake, and the edges began to crumble, as the rapidly shrinking sphere of wild magic closed on them.

They could not reach the children, although Mokona managed to get Syaoran and Sakura safely outside of the perimeter of the collapsing circle. With an effort that left his body shaking, Fai blasted all his magic against the wall of destruction; he created a breach wide enough to admit him, but when he tried to pull Kurogane after him, it proved fruitless. An entire world was closing on Kurogane; the magical forces involved were far too great for any man, no matter how desperate.

Kurogane staggered to his knees as the hurricane wind buffeted him; his ears rang with more than the noise of the maelstrom. Tomoyo's ward had deflected the blow that should have eviscerated him, but he was still badly injured; he could feel the dizziness and nausea that warned of bloodlessness, sapping his limbs of their strength. He remembered Tomoyo's curse, her warnings; that if he disobeyed her injunction and killed another, their death would rebound on him. Was this what she had meant? Had she foreseen this?

Kurogane did not want to die. He wanted to survive, to reach his home, to show Tomoyo all he had learned. He wanted to make sure the princess would be all right, he wanted to get to know the kid better, he wanted to find the man with the bat sword and settle things with him once and for all. There were so many things he still wanted to do with his life; not the least of which, he wanted to know what Fai's face looked like when he was happy, truly happy.

But more than any of those things, if he had to die, he did not want to drag anyone else down with him. Knowing how to accept death was part of a shinobi's training, part of his upbringing as a warrior. Your own life was never as important as the goal you sought to defend with it.

And so he gripped Fai's hand tightly one last time, wishing as he did so that he could pass all his last wishes, all his passion for living on to this man who had been robbed of all his; and then he opened his hand, leaving Fai's grip on his wrist as the only contact between them. He met Fai's gaze with his own, and shouted, "Go!"

Fai cried out, wordlessly; tears were streaking down from his good eye, and his expression was sere and frozen, almost as though he were the one trapped in the closing world and not Kurogane. Magic bloomed and flared around him, but sputtered out almost immediately; he had nothing left to give, and magic would not buy them safe passage now.

Why won't you let me go? Kurogane wondered. You saw me destroy your brother's image. You saw me murder your king. By all rights you should hate me for what I've done. He knew it had been necessary, he couldn't regret what he'd done; but he knew that Fai had loved Ashura, and knew equally that he would never forgive the man who slew Tomoyo, no matter how dire the need. Now, now was the right time for Fai to pretend indifference, push him away, let go...

The closing world and the slithering rush of collapsing magic was almost deafening now; so it was in an almost white noise of silence that he saw Fai's eye widen with realization, saw his chest expand with indrawn breath. He couldn't possibly hear Fai's voice over the din, but he could easily read the shape of his lips. "Your body... at the center of the vortex. Your blood... runs in my veins..."

His expression hardened to a sudden resolution, and he gripped Kurogane's wrist with one hand, the other one lunging past the closing portal to Kurogane's side. He grabbed up Kurogane's sword from where it had fallen, still wet with Ashura's blood; and with one swift motion he brought it up and around.

Blood arced in a spray, and the severed arm fell together with Kurogane's sword to the churning, shifting ground. Kurogane stared, numb with shock and horror at what Fai had just done. Fai, his face white, his teeth gritted against shock and pain, seized him by the cape and pulled him forward with a sharp yank; as always, the unnatural strength in that slim frame took him by surprise, and he never even thought to resist it.

And then they were outside the deadly shell of collapsing reality; Mokona's familiar transport magic enfolded them, and took them home.

~end.