Afterward, Tosen Kaname was confined to a secret cell deep within the Nest of Maggots. His injuries had mostly healed under Hasumi Ren's Kaido treatment, and his Spiritual Pressure was gradually stabilizing, but he remained in a comatose state and would not wake up anytime soon. At the same time, Urahara had placed multiple layers of seals on him to ensure absolute security, waiting for the precise moment his presence would be required to let him out.
On this day, Ren was tuning the Hogyoku in Aizen's laboratory, calibrating the complex rows of data. Royd, disguised as Tosen Kaname, sat on a chair in the corner, quietly logging the experimental parameters with a serene, wordless expression.
Suddenly, Ren's senses caught a peculiar anomaly. An unfamiliar yet recognizable trace of Spiritual Pressure wafted in from outside the laboratory. He remembered this presence—it belonged to the Quincy he had encountered before.
As Ren followed Aizen out of the laboratory, Quilge stepped forth from the shadows. His circular glasses reflected a chilly glint, masking the expression in his eyes. He scanned the room, his gaze lingering on Tosen for a split second before shifting away noncommittally to settle on Aizen.
"Lord Aizen, we meet again."
Aizen looked at Quilge, the corner of his mouth curving slightly. "It appears your leader has reached a decision."
Quilge nodded. "Lord Haschwalth has agreed to your terms. In exchange for safeguarding the secrets of the Wandenreich, our forces will aid you in battle when you move against the Seireitei in the future."
Aizen's smile widened. "Excellent."
Quilge extracted a document from his robes and placed it on the workbench. Wrapped in a pristine white cover, the document bore no text, featuring only a silver crest—the emblem of the Wandenreich's Quincy.
"This is our covenant: a pact of non-aggression, shared intelligence, and mutual opposition against the Gotei 13. The alliance takes effect from the moment of signing. Should either party compromise the other's existence, the pact is automatically voided, and we shall become enemies."
Aizen picked up the document, glanced over it, and set it back down. "A written contract is unnecessary. A verbal agreement will suffice."
Quilge's brow twitched slightly as his eyes searched Aizen's face. Then, he gave a firm nod. "A verbal agreement it is, then."
The two locked eyes, neither speaking further. A subtle tension permeated the air—the unspoken understanding of mutual exploitation. The alliance was a farce, but the shared interests were genuine. Once the Gotei 13 was sufficiently weakened, this pact would become as flimsy as paper, destined to be torn apart by both sides simultaneously.
Quilge turned to depart. Pausing to glance sideways at Tosen, a meaningful curve touched his lips. "Your subordinate seems to have recovered nicely."
Tosen kept his head lowered, remaining silent. Aizen's gaze shifted toward him. "You needn't concern yourself."
Quilge offered no further response, striding into the darkness. Shadows churned beneath his feet like a disturbed pool of black water, slowly swallowing his form. A few breaths later, the shadows settled back into stillness, as though nothing had ever transpired.
Aizen stood where he was, staring at the spot where the shadows had vanished, lapsing into a brief silence. His gaze was deep and unreadable, as if pondering something. Then, he turned around to look at Tosen. "Have your wounds completely healed?"
Tosen bowed his head. "I am perfectly fine now. Thank you for your concern, Lord Aizen."
Aizen nodded. "Good. In that case, resume your lead over the Hogyoku experiments. Have Ren assist you so we can proceed to the next phase."
Tosen offered a slight bow. Aizen patted his shoulder before taking his leave first. Ren noticed that the moment Aizen stepped away, Tosen's fingers tightened ever so slightly. The gesture was incredibly faint and fleeting; had Ren not been paying deliberate attention, it would have been impossible to spot.
'This counterfeit Tosen will undoubtedly run into numerous issues once the actual experimentation begins. How will he cover his tracks then?' A faint smile tugged at the corner of Ren's mouth. He found himself looking forward to Aizen's reaction when the time came. 'Better yet, what kind of face will Aizen make if both Tosens were to appear at the exact same time?'
Night fell, and the streets of the Seireitei were bathed in a crisp, cool moonlight. Tosen walked alone on the path back to the Squad 9 barracks, his slow pace suggesting deep thought. As he neared a secluded alley entrance, he suddenly ground to a halt.
Towering walls flanked the passage, where the Reishi lamps cast a dim, chilly illumination that left the alley half-shrouded in shadows.
"Show yourself," his voice was low, yet remarkably crisp in the dead silence of the night.
Quilge slowly stepped out from the darkness. His footsteps were light, making virtually no sound at all. "Excellent perception, Royd," Quilge remarked placidly.
Tosen gave a slight nod. "What are my directives?"
Quilge stepped up to him, dropping his voice. "Report the intelligence you've gathered so far. Is the existence of the Hogyoku verified? Furthermore, how difficult would it be to seize it?"
Tosen lowered his head, pondering briefly. "The Hogyoku is real. Aizen has been utilizing it to conduct Hollowfication experiments in an attempt to shatter the boundary between Soul Reapers and Hollows. Moreover, he has his eyes on another Hogyoku in someone else's possession."
Quilge's brow arched. "Whose?"
"Urahara Kisuke, the Third Seat of Squad 2," Tosen replied smoothly. "He holds a second Hogyoku. Aizen's strategy is to wear down the Gotei 13 first. Once the opportunity ripens, he will wrest that Hogyoku from Urahara and fuse the two spheres together to attain a power that transcends all existence."
Quilge's eyes narrowed into slits, his gaze sharpening. "Two Hogyokus... fascinating." He paused, his eyes pinning Tosen. "Lord Haschwalth's order was to seize the Hogyoku when an opportunity presents itself. However, since it is merely an incomplete prototype... we shall await his further judgment."
Tosen nodded. "Furthermore, if we are to truly seize the Hogyoku, I will require reinforcement. Operating alone under Aizen's watchful eye is an impossible task."
The corner of Quilge's mouth curled slightly into a faint, chilly smile. "Rest assured, once the preparations mature, the Sternritter will make their move. For now, you need only perform your duties: monitor Aizen, gather intelligence, and await the signal."
Tosen bowed his head. "Understood."
Without another word, Quilge turned and melted into the shadows, this time without looking back. The darkness churned beneath his feet, slowly swallowing his frame. A few breaths later, tranquility returned to the alleyway.
Tosen stood in place, staring at the spot where the shadows had vanished for a long time. Withdrawing his gaze, he turned and walked toward the alley exit. As he emerged and made his way back toward his current quarters at the Squad 9 barracks, an unexpected figure materialized before him.
Ren.
Clad in his Shihakusho with his Zanpakuto slung at his waist, Ren's expression was placid, looking as if he had simply happened to pass by. Yet, Tosen did not believe for a second that this encounter was coincidental.
"Your physical recovery seems to be progressing well. Do you need me to administer another treatment?" Ren offered.
Uncertain of Ren's underlying intentions, Tosen opted for silence. He merely sidestepped, brushing past Ren's shoulder. "You needn't bother."
His footsteps echoed crisply along the deserted street, gradually fading into the distance. Ren neither turned around nor spoke another word. He simply stood where he was, watching Tosen's silhouette dissolve into the night. Withdrawing his gaze, he turned and walked back toward the Squad 4 barracks.
Time glided by imperceptibly amidst the waiting. As the days rolled on, the surface of the Seireitei remained tranquil, but the undercurrents beneath the water were surging with increasing velocity.
On this day, while Ren was conducting his routine duties at Squad 4, a transfer order arrived from Central 46. Yamada Seinosuke was being reassigned.
Though the directive seemed sudden, it was entirely anticipated. The expansion of the Shin'o Institute of Medicine had concluded, requiring an experienced medical expert to assume the mantle of Chief Director. Weighing all pros and cons, Yamada Seinosuke was the most fitting candidate for the role.
That afternoon, the sky hung in a somber grey. Yamada Seinosuke was packing his belongings inside the Squad 4 barracks. His movements were deliberate and slow, as though bidding a final farewell to this sanctuary. Several familiar squad members gathered around him, some offering partings, others seeing him off. Yet, everyone understood that since Yamada would be catering to the nobility at the Shin'o Institute of Medicine, this transfer was effectively a major promotion.
Ren stood among the crowd, watching Yamada from the rear. After all, Yamada had imparted a wealth of knowledge to him regarding Kaido; out of basic respect and courtesy, he had to see him off.
"Lieutenant Yamada, will you ever come back?" a young squad member finally burst out, a tremor in his voice.
Yamada Seinosuke offered no answer, merely letting out a soft chuckle. His gaze swept across every individual present before finally locking onto Ren. "Do a good job." Just four words, but his tone carried a profound weight, as if delivering a silent entrustment.
Ren nodded. "Rest assured, Lieutenant Yamada."
Yamada said nothing more, picking up his luggage and walking out through the grand gates of Squad 4.
A few days later, in the Squad 4 Captain's office.
Unohana sat behind her desk, a document spread out before her. Sunlight streamed through the window, casting a warm, golden pool of light onto the floorboards. The air was infused with a faint fragrance of medicinal herbs, exuding the same serene tranquility as any other day.
Ren stood opposite her, holding the day's diagnostic reports. The moment Unohana summoned him, he had already faintly anticipated what was coming.
"Seinosuke has departed, leaving the Lieutenant position vacant," Unohana's voice was perfectly placid, as though stating a matter of little consequence.
Ren remained silent. He knew Unohana hadn't called him here merely for a standard handover of duties. Unohana raised her head to look at him, her gentle eyes harboring a profound seriousness that Ren rarely witnessed.
"Starting today, you will assume the position of Lieutenant."
Ren's AIC fingers twitched slightly. Lieutenant. Even though his current strength was more than enough to handle the position, a trace of surreality washed over him when it actually materialized. From an ordinary student at the Shin'o Academy, to a member of Squad 2, then to the Fourth Seat of Squad 4, and finally to Lieutenant. Barely two years had flown by. Across the entire Seireitei, such a promotion velocity was downright astounding.
He fell silent for a brief moment before bowing his head. "Thank you, Captain."
Unohana gave a soft nod. "Your capabilities are more than worthy of this position." She rose from her seat and walked over to the window, turning her back to him. "Squad 4 is a medical relief squad that rarely engages in direct combat, but that does not mean it lacks importance. On the contrary, it is paramount, for only those who are alive can continue the fight."
She turned around, locking her eyes on Ren. "Your mastery of Kaido is apparent to everyone within Squad 4. You are fully capable of undertaking the responsibilities of a Lieutenant; no one will utter a single word of gossip. From this point forward, work hard—for the sake of the Soul Society, and for your own."
Ren looked at her, remaining quiet for a moment. The sunlight bathed her frame, rimming her silhouette in a soft, golden fringe. Her expression was serene, yet a profound depth resided in her eyes—one Ren had never perceived before.
"I will not fail your expectations."
Hearing Ren's response, Unohana gave a firm nod. "Then remember those words. From now on, you are the Lieutenant. You are not only responsible for yourself, but for every single soul within this squad."
Ren bowed his head. "Understood."
After clarifying the relevant protocols, Ren rose and exited the Captain's office. Even as a newly appointed Lieutenant, Ren maintained the exact same stoic composure as before. Unohana simply stood in place, watching Ren's departing form as a soft curve traced the edge of her lips.
A few days later, Ren returned once more to Aizen's secret laboratory.
The Hogyoku rotated slowly inside its container, and Aizen stood before the culture medium, observing the churning mass of Spiritual Pressure within. His hands were clasped behind his back, his posture elegant, his gaze deep.
Tosen Kaname stood behind him, hands hanging loosely at his sides, his expression tranquil. His Spiritual Pressure had fully returned, and his wounds had knit shut, but he spoke sparingly, quietly executing his assigned duties. Yet, Ren knew that this counterfeit Tosen was about to face his ultimate trial: spearheading the experiments. He wondered how the impostor would bluff his way through it.
Ren stood before the workbench with a logbook in hand, his eyes scanning the Spiritual Pressure fluctuation charts. His pen glided smoothly across the paper, recording every single data point.
"Ren," Aizen's voice drifted over from across the room.
Ren looked up.
"I heard you have been promoted to Lieutenant. Congratulations."
"Thank you, Lieutenant Aizen. It is nothing of great consequence," Ren replied smoothly.
Aizen nodded, seamlessly steering the topic back to the Hogyoku experiments. "The Hogyoku experiments are ready to advance to the next phase. I intend to gather several Hollows to attempt their Arrancarization."
Ren's fingers stiffened slightly.
Arrancarization—this was the pivotal stride in Aizen's Arrancar project, and his opening gambit for conquering Hueco Mundo. Ren's Hollow avatar—the white Hollow currently sealed inside the containment tank—had been kept under wraps, waiting for the perfect opening. Was it finally time to deploy it?
"When do we begin?" Ren inquired, keeping his voice perfectly level.
Aizen stepped back to the workbench, picked up a document, and handed it to him. "In three days. You will be responsible for preparing the experimental materials and assisting Tosen in executing the project."
Ren took the file. "Understood."
He turned and walked toward the deeper recesses of the laboratory.
There, inside the sealing tank, his Hollow avatar lay quietly. The white Hollow possessed a slender, elongated frame, a bone mask completely obscuring its face. It slowly cracked its eyes open, revealing a dark crimson gleam. Ren stood before the container, staring at his clone. Inside the tank, the Hollow similarly tilted its head up, its dark red eyes locking onto his.
Ren withdrew his gaze, turning to walk over to an adjacent container. He eyed the Hollows confined inside and gave a slight nod. He then selected a few Hollows that were in optimal condition to prepare them for the upcoming test. As for his own Hollow avatar, the timing wasn't right to deploy it just yet.