A/N: Spoilers for the SS arc onward. This one-shot takes place immediately post-Ichigo-fight, before Byakuya takes that wicked hit from Shinsou on Rukia's behalf. Sen here is based on the Sen we know from the zanpakuto filler arc, which might as well be canon in my head from here on out. The title just implies, at least to me, the impact that the Ichigo fight has on Byakuya's actions/personality/identity from there on out. I tend to think of it as his own little personal Armageddon.
Kuchiki Byakuya fled Seireitei.
That he fled for Rukongai would have surprised those who thought they knew him—those who imagined that the elegant, graceful heir to the Kuchiki family, who always wore his haori and shihakusho draped just so, would not or could not survive in the rough-and-tumble world of the far-flung districts. But right now the last thing Byakuya wanted to see was the pristine whiteness of his home. He wanted the smell of earth and dampness and the sight of a gray sky. Overwhelmed with hopelessness inside, he wanted to immerse himself in hopelessness outside, too.
And what was more hopeless than the Rukongai?
Working on desperation and sheer adrenaline, he used his shunpo to avoid the more populous areas, seeking a patch of gray, shriveled, abandoned forest. Hisana had shown him these places, on some of their walks—the colorless, bleak parameters of the only world she'd known before he introduced her into his. When he finally stopped in an enclave of spindly, malnourished trees, his knees buckled.
Byakuya was unaccustomed to this kind of pain, the pain earned in defeat. Pain in victory was something else altogether; triumph eclipsed physical frailty, numbed the injuries until such time as they could be dealt with. But this—this—
His shikuhasho and haori stuck wetly to his body in various places, sodden with blood and sweat. Still more blood trickled down his forehead to clot in his long lashes and hinder his vision. That Kurosaki Ichigo had not witnessed his collapse was the only thing that made it remotely bearable. Kurosaki Ichigo. Satisfied that he was alone, Byakuya issued forth a stream of curses crude enough that even Renji would have blinked.
He might not have won, if not for that—for whatever it was Kurosaki had become, that disconcerting hybrid of hollow and shinigami. Staring his own defeat in the face, Byakuya nevertheless refused to concede totally; without that mask, he reasoned, Kurosaki Ichigo could never have beaten him. That one insistent attack—Getsuga Tensho—was the only thing in the boy's arsenal. And no just-acquired bankai would ever be enough to take down his blade, his Sen—
"Senbonzakura!" Terror assailed him, pushing out even pain. Quickly he looked to his palm, recalling those last few moments of his encounter with Kurosaki, the glimmer of that last bladed petal shimmering, fading in his palm. "Senbonzakura!" He called out, desperately. Had his zanpakuto been harmed? Would he be abandoned entirely in his defeat? The thought pained him, left a nauseating emptiness in its wake.
Faint, but there. Byakuya sagged in relief, unsheathing his zanpakuto and resting it across his lap. "Senbonzakura." He found he did not quite know what to say. Defeat was new for him. Ashamed, he did the only thing that came to mind, and polished the zanpakuto's blade free of blood and grime with the filthy sleeve of his shikuhasho. The blade blurred beneath his vision for a moment, and he blinked away the burning in his eyes. "I am sorry. I have failed you." Replacing the blade, he sighed. I have failed myself.
"No less than I have failed you, Byakuya-sama." The words were tinged with regret, and came not surprisingly close by; Byakuya started at the sight of his zanpakuto leaning against a tree, watching him. Senbonzakura didn't look much better than his wielder; his regal clothing, too, was battered and blood-soaked, his ferocious mask marred with cracks.
Byakuya looked away. Their previous meetings had been on more felicitous occasions; this was an entirely new circumstance. Voice pitched low, he murmured, quietly, "I do not wish to lose my standing in your eyes with this defeat."
A very undignified snort from his zanpakuto. "It's not over, Byakuya-sama," Senbonzakura noted, and then straightened. Though his mask hid his face, his agitated movements and the passion in his voice were enough to reveal his excitement. "The next time we meet Kurosaki Ichigo, we will teach him. He will learn to fear us, and—"
"—and he will taste more of our blade than he tasted this time, Byakuya-sama! Next time that untutored child will not get up again. I do not care if he brings back that mask, Byakuya-sama, I won't lose. I'll—"
"Senbonzakura." The zanpakuto halted his enthusiastic speech obediently. The captain of the Sixth Division sighed. "There will be no next time." He paused, felt the sting of his wounded pride, and amended, "At least not over this."
He felt Senbonzakura's gaze despite not being able to see it. To his surprise, his zanpakuto did not object, but walked over to stand beside him. Gloved fingers tilted his chin up. "Whatever you think is right, Byakuya-sama, I will fight for."
He closed his eyes. "Thank you, Senbonzakura." The touch disappeared, and he sighed, keeping his head tilted up without opening his eyes. In his mind's eye he saw that one glimmering petal fade in his palm. "Promise me that you will never fade from me," he whispered, troubled by the image.
The zanpakuto leaned down over his crouching wielder, only a few inches from his face. "I promise," he replied, simply, and then added, "Byakuya-sama, I will never die for you. Nor will you ever die for me. That is not the way of shinigami and their zanpakuto. When we fade, you and I, we will fade together."
"Then," the captain said simply, "we must depart. There are issues that must be considered." But he didn't rise, curtained in the sweeping fall of his zanpakuto's silken dark hair, enjoying the closeness he scarcely permitted himself in day-to-day life. It felt good, like this—to close his eyes in the presence of another human being, to rest, to feel the stir of someone else's breath. The unexpected joy of that intimacy made him momentarily forget his throbbing wounds.
"Were we not," Senbonzakura asked softly after a moment, "magnificent?"
Byakuya thought of it all: the beautiful white blaze of hakuteiken, the dizzying power coursing through him, those stunning, jagged white wings, the radiance. The pride he thought shattered after his fight rose again—bruised, but not broken. "Yes," he murmured. Twining Senbonzakura's long dark hair around his fingers, he pressed his lips against the silken softness of it. "We were."
He did not have to see beneath his zanpakuto's mask to know that Senbonzakura was smiling. "Then you must promise me in turn," his zanpakuto entreated him, "that we will do that again, Byakuya-sama. We are warriors."
The shriveled trees and gray skies of Rukongai still seemed hopeless, but Byakuya found that his own quiet agony had somewhat diminished. "I promise, Senbonzakura," he said softly. He felt the gentle stroke of hands over his hair, and then the presence surrounding him dissipated. Byakuya stood painfully. When he took a step, and looked back over his shoulder, his zanpakuto was gone. So was his adrenaline. Every limping step back to his division made his body scream in pain. The thought of Rukia upset him, the thought of Renji's lifeless body disturbed him, the thought of Kurosaki Ichigo's earnest eyes dismayed and confused him. Had it not been for his considerable fortitude he might not have made it back at all, and he found himself pathetically relieved to arrive at the Sixth Division headquarters. Once in his office, he took the opportunity—perhaps the last for some time—to lean against a wall and allow himself a moment of vulnerability.
Much had changed. Much still would change. What was to be done, now? He had promised not to hinder Kurosaki Ichigo from here forward, but—what path was he now to take? Curiously, Byakuya opened his trembling palm and saw, to his delight, a single pink petal resting in the cradle of flesh. We are warriors, he thought, in silent agreement. And warriors, wise ones, did not make the same mistakes twice.
Whatever path he chose to take, he knew Senbonzakura would follow.