The six years following the unsettling incident with the three Adjuchas in the Rukon District passed with a deceptive semblance of normalcy. The overt threat had been neutralized, the rescued villagers resettled, and the official reports filed away, yet the undercurrent of unease within Soul Society remained, a subtle tremor beneath the surface of everyday life. For Kisaragi, life within the Second Division settled into a demanding but structured routine of clandestine missions, routine patrols through the Rukon District, and the ever-present responsibility of his role as a Corps Commander within the Onmitsukido.
The incident, however, had served as a significant catalyst. Kisaragi's decisive and overwhelming display of power had irrevocably altered his standing within the Second Division. The initial skepticism that had greeted the former Fourth Division healer had been thoroughly eradicated, replaced by a profound respect bordering on awe. The tale of the "healer" who had effortlessly dispatched three Adjuchas without even drawing his Shikai had become a whispered legend, a testament to a hidden strength that had surprised even the most seasoned operatives of the Onmitsukido.
Taking his responsibilities seriously, Kisaragi dedicated a significant portion of his time to the rigorous training of his one-hundred strong Inner Court Troop. He pushed them relentlessly, emphasizing the core tenets of their division: speed, stealth, and unwavering efficiency. Shunpo remained a primary focus, its mastery deemed crucial for rapid communication and swift deployment. Kisaragi personally oversaw their drills, his own near-flawless technique serving as both an inspiration and a demanding benchmark.
He imparted subtle nuances, refined movements, and the crucial understanding of spiritual energy manipulation for bursts of unparalleled speed. The results were undeniable; the entire Corps showed marked improvement, their agility and swiftness becoming a testament to their commander's rigorous tutelage.
The six subordinates who had accompanied him on the perilous Rukon patrol became unintentional evangelists of Kisaragi's prowess. Their firsthand accounts of the battle, recounted with wide-eyed disbelief and fervent admiration, cemented his almost mythical status within the division. They spoke in hushed tones of the azure flames of his Hadō, the golden restraints of his Bakudō, and the unnerving power he wielded without ever releasing his Zanpakuto. Their awe was infectious, further solidifying Kisaragi's position and earning him the implicit trust of his subordinates.
Despite his demanding duties within the Second Division, Kisaragi never lost sight of his primary objective: to amass sufficient power to confront the looming darkness he knew was steadily approaching. He continued his own relentless training, but recognized that his fundamental skills had reached a plateau where significant improvement through solo practice was becoming increasingly difficult. The true crucible for growth now lay in high-stakes duels against formidable opponents.
The constraints of his role within the Onmitsukido, however, made casual sparring sessions with Byakuya a risky endeavor. Unexplained absences or clandestine meetings could draw unwanted attention, potentially jeopardizing his position and even raising suspicion within the watchful eyes of the Second Division. Therefore, Kisaragi strategically shifted his focus towards the elusive final stage of Zanpakuto mastery: Bankai.
Months after the Adjuchas incident, Kisaragi returned to the familiar, secluded training ground in the outskirts of the Rukon District. This hidden sanctuary, far from the prying eyes of the Seireitei, had been his refuge for years, a place where he could push his limits without fear of observation. It was here, amidst the jagged rocks and twisted trees, that the spiritual pressure around him reached a critical threshold during one of his intense solitary training sessions. The air crackled with raw, untamed energy, and a palpable sense of ancient power filled the desolate space. Before him, shimmering into existence as if drawn from the very fabric of his soul, materialized Byakko.
The manifested Zanpakuto spirit was a breathtaking spectacle: a colossal white tiger, its fur radiating a soft, ethereal luminescence, its eyes burning with an ancient wisdom and a regal, untamed power. A low, resonant growl rumbled through the air, carrying a weight that seemed to vibrate the very ground beneath Kisaragi's feet.
"You have finally reached this point, Kisaragi," Byakko's voice echoed directly into his mind, a deep, sonorous tone imbued with a hint of ancient satisfaction. "The path to Bankai lies before you, a treacherous ascent demanding your utmost strength and resolve."
The magnificent tiger lowered its massive head, its luminous gaze locking onto Kisaragi's. "But this final step is not a mere formality. It is a trial, a crucible in which your spirit and mine must become one. To unlock the true, devastating potential of my Bankai, you must prove your worth. You must defeat me, not just in the spiritual realm, but in a battle that tests the very limits of your being, here, in this world."
And so, the following six years became a delicate balance for Kisaragi. He maintained his demanding routine of training his Corps, executing his assigned missions and patrols with unwavering efficiency, and subtly keeping an eye out for any further anomalies that might hint at Aizen's machinations. But woven into the fabric of his daily life were the increasingly frequent and intensely challenging duels against his materialized Zanpakuto spirit, Byakko, in the secluded outskirts of the Rukon District.
He had long since lost count of the number of times he had faced the majestic white tiger in this desolate sanctuary. Each encounter was a brutal test of his evolving skills. Byakko moved with a primal ferocity, its ethereal claws tearing through the air, its spiritual roars carrying concussive force. It exploited Kisaragi's weaknesses, forcing him to adapt and grow in ways that solo training within the Seireitei could never replicate.
One evening, after completing his routine reports, Kisaragi made his way to his secluded training ground, the air carrying the faint echoes of past spiritual clashes. The twisted trees stood as silent witnesses to his relentless pursuit of power. Closing his eyes, he focused his inner energy, drawing forth the magnificent white tiger once more.
"Byakko," Kisaragi began, his voice calm but carrying a newfound confidence, the familiar scent of the Rukon earth beneath his feet. "I challenge you again, here, in our familiar battleground."
The white tiger's luminous eyes narrowed, a low growl rumbling in its chest, the dust swirling slightly around its massive paws. "You are persistent, Kisaragi. Have you finally found the strength to overcome me in this realm?"
"I believe I have," Kisaragi replied, unsheathing Byakko, the polished blade reflecting the fading light of the setting sun. The air around him crackled with anticipation, the desolate landscape becoming their arena.
The ensuing battle was the most intense they had ever engaged in within the physical world. Byakko moved with a speed and ferocity that pushed Kisaragi to his absolute limit, its massive form tearing through the desolate landscape. The clash of their spiritual energies shook the very air, the jagged rocks around them pulverized by their furious exchange. Kisaragi utilized every skill he had honed over the past thirty years – his enhanced Shunpo allowing him to evade Byakko's devastating attacks across the uneven terrain, his masterful Zanjutsu meeting the tiger's ethereal claws with precision and power amidst the twisted trees, his strategic Kidō creating openings and disrupting Byakko's movements against the backdrop of the desolate horizon, and his refined Hakuda allowing him to engage in close-quarters combat when necessary, using the very environment to his advantage.
"You have grown stronger, Kisaragi," Byakko's voice echoed in his mind during a brief respite in their furious exchange, the wind carrying its ethereal growl across the desolate plains. "Your connection to this world has deepened."
"And you have pushed me to become stronger, Byakko," Kisaragi retorted, his breath coming in ragged gasps, the dust swirling around his feet, but his eyes burning with unwavering determination against the darkening sky. "For that, I am… grateful for this harsh but necessary training ground."
The final moments of the battle were a blur of motion and raw power against the backdrop of the desolate Rukon outskirts. Kisaragi, channeling every ounce of his spiritual energy, unleashed a furious barrage of attacks, his movements now flowing with an almost preternatural grace across the uneven terrain. He anticipated Byakko's strikes, countered with precision, and finally, with a decisive blow that resonated deep within his soul and echoed across the desolate landscape, he struck a vital point in the tiger's ethereal form.
Byakko roared, not in pain, but in a sound that held a strange mixture of defeat and profound satisfaction, the sound echoing across the desolate plains. Its luminous form shimmered, the intense spiritual energy receding as it began to dissipate into the familiar Rukon air.
"You have done it, Kisaragi," Byakko's voice echoed one last time, softer now, filled with a sense of acceptance as its form faded into the twilight. "You have finally proven yourself worthy, here in this world that you strive to protect, in our secluded battleground." The magnificent white tiger dissolved completely, flowing back into the sealed form of Byakko, its ultimate power now fully integrated with Kisaragi's very being, the desolate landscape once again silent.
A surge of overwhelming spiritual energy coursed through Kisaragi, a power so immense it felt as if the very fabric of his soul had been reforged. The desolate world around him seemed to hum with a newfound intensity. He had done it. After six long years of relentless training and countless grueling battles against his own Zanpakuto spirit in the secluded outskirts of the Rukon District, Kisaragi Shiba had finally achieved Bankai.
Unbeknownst to him, his former training partner and enduring friend, Byakuya Kuchiki, had reached this formidable milestone a year prior. The weight of his noble lineage, his prodigious talent, and the quiet grief that still fueled his relentless pursuit of strength had propelled him to Bankai, a silent testament to the enduring, albeit now more subtly expressed, bond that still connected the two former Academy rivals, even as their paths diverged within the intricate and hierarchical structure of the Gotei 13.
Thirty years had passed since Kisaragi's reincarnation, a significant chapter in his long journey now complete, his Bankai forged in the desolate silence of the Rukon outskirts. The shadows held a power that was finally ready to be unleashed upon the world.