Kageroza Inaba retrieved three test tubes from his coat with a satisfied smile.
"Heh heh, what an unexpected delight…"
He had initially only planned to collect the spiritual pressures of Kaien Shiba, the lieutenant of the 13th Division, and his wife, Miyako Shiba, the third seat. But unexpectedly, the captain of the 11th Division had also intervened. Obtaining the spiritual pressure of this "Strongest Shinigami" meant that his dream was practically within reach! All that remained was to create a suitable vessel for it.
Inaba's eyes glinted with anticipation as he recalled Ailin's display of power from seventy years ago. Ailin, during his time as lieutenant of the 2nd Division, had stormed the 12th Division's barracks, single-handedly overwhelming the entire division with his spiritual pressure and his mastery of golden spatial ripples.
If Inaba could create a Mod Soul with Ailin's abilities, who in the entire Soul Society could possibly stand against his army?
With deft movements, Inaba removed the stoppers from the three test tubes. Three distinct streams of reishi particles, each a different color, rose from the vials, swirling and merging as they were drawn into a fourth test tube in his hand. They coalesced within the tube, transforming into a shimmering blue liquid.
Inaba carefully sealed the vial, "Soon… Soon, all that remains is…"
He turned and vanished into the night.
…
Beneath a fiery red sky, a towering wooden cross stood atop a desolate hill. A man, bound to the cross by black bandages, resembled a macabre mummy.
Buzz!
A golden spatial ripple materialized in the air, and Ailin stepped through the portal, arriving at this desolate location. It was his "Innate Domain: Unlimited Blade Works."
With a flicker of Shunpo, he appeared before the bound figure, Sōsuke Aizen.
"It's been a while, Aizen."
"Indeed, Captain Ailin. It has been quite some time since we last spoke. However, I see you almost every day." Aizen replied with a faint smile.
Despite being defeated by Ailin over two decades ago and imprisoned within this strange realm, Aizen's expression remained unchanged, as serene and composed as ever.
It was as if this setback meant nothing to him.
Hearing Aizen's stubborn insistence, Ailin simply chuckled. Back in his previous life, Aizen had been his favorite antagonist. However, at his peak, Aizen's rapidly growing power had destabilized his mind. Compared to Ichigo Kurosaki, he had come across as a bit of a "clown."
Fortunately, Aizen had eventually recognized his own folly. His power had exceeded his control, threatening to consume him. He had chosen to reject further evolution, to preserve his sense of self.
The Hōgyoku, responding to his desire, had ceased its influence, preventing him from evolving further. This had ultimately led to Aizen's defeat at the hands of Kisuke Urahara, who had sealed him within the Kidō embedded within his half of the Hōgyoku.
"Aizen, we had an agreement. Now, I've come to fulfill my end of the bargain."
"Oh?" Aizen's smile didn't waver. It was as if Ailin's decision had been anticipated all along.
"Captain Ailin, I told you before, we are the same. This world, though it underwent a massive transformation a million years ago with the Soul King's creation of the Human World, Hueco Mundo, and Soul Society, with the separation of life and death… It has stagnated ever since.
Nobles hoard power, lording over the commoners, who struggle to survive… The Soul Society's million-year history is a monotonous repetition, devoid of any real change…
In my view, there's no fundamental difference between this world and the chaotic void that preceded it. They have both reached a state of stagnation, devoid of any progress.
Both you and I, we seek evolution, transcendence. The current state of the Soul Society is incompatible with our aspirations. We are the wind that will propel this stagnant world forward, forcing its gears to turn and advance. In our quest to reshape this world, we will either succeed in changing it, or we will be crushed by it."
"Captain Aizen, you truly are a master of illusion, not just with your Zanpakutō, but with your words as well. Your ability to manipulate emotions is far superior to mine."
With a wave of his hand, Ailin dispelled the black bandages that bound Aizen, transforming them into Kidō symbols that converged on his chest, leaving only a small black dot.
Boom!
With the seal broken, Aizen spread his arms wide, unleashing his immense spiritual pressure. It surged through Unlimited Blade Works, creating waves of reishi particles that crashed against the desolate landscape.
"Oh?" Ailin was surprised. Even after twenty years of imprisonment, Aizen's spiritual pressure had increased significantly. It had reached the limits for a captain, just a sliver away from the absolute limit for a Shinigami.
Aizen extended his hand towards Ailin, and a blue, glowing orb materialized in the air before him. It was the half-formed Hōgyoku created by Aizen. It had been resting in Ailin's pocket. Now, it flew towards Aizen, drawn by an invisible force.
Boom!
With the Hōgyoku's aid, Aizen's spiritual pressure shattered its final barrier, reaching the absolute limit for a Shinigami.
"Well done, Captain Aizen." Ailin applauded. "I never imagined the connection between you and the Hōgyoku was so strong, that its power could even influence you within my Innate Domain… It seems I've underestimated both you and the Hōgyoku."
Witnessing Aizen's breakthrough, Ailin realized that even if he hadn't chosen to release him, Aizen, with the Hōgyoku's influence, would have eventually reached the limit of a Shinigami's power and broken free from his seal.
Of course, escaping the seal was one thing, escaping Unlimited Blade Works was another.
However, if Aizen had the power to break free but chose to remain imprisoned, he could potentially pose a serious threat to Ailin in the future. For instance, if Ailin encountered an enemy who required the use of his Innate Domain, Aizen, striking at a crucial moment, could easily turn the tides, potentially leading to Ailin's defeat.
"It was thanks to you carrying the Hōgyoku, Captain Ailin, that I was able to draw upon its power. Your connection to this space provided a conduit for its influence."
Aizen's words were accurate. Unlimited Blade Works, Ailin's Innate Domain, was a manifestation of his Zanpakutō.
The Zanpakutō within this space could communicate with him through their shared connection.
Aizen, sealed within Ailin's soul, wasn't much different from a Zanpakutō spirit.
After all, the original Zanpakutō were forged using the souls of Hollows and Shinigami.
Ailin's clone, carrying the Hōgyoku at all times, had inadvertently provided Aizen with a loophole.
"Excellent. This breakthrough only strengthens my confidence in your abilities, Captain Aizen. Now, allow me to catch you up on the events of the past few decades. I wouldn't want you to be out of touch with the world."
With that, as Aizen looked on in bewilderment, Ailin drew his Zanpakutō.
"Shatter – Kyōka Suigetsu!"
A faint light flickered in Aizen's eyes.
Images flooded his mind.
Ailin's clone, entering Hueco Mundo, subjugating the Espada, appointing Tier Harribel as the new third Espada…
In the Soul Society, a Hollow, born from Ailin's Hollowfication experiments, possessing the combat instincts of a Shinigami…
Ailin, visiting the Shin'ō Academy, teaching the students the four Shinigami arts, showcasing the power of his Zanpakutō, Kyōka Suigetsu…
Ailin, acting as an examiner for the Shin'ō Academy graduation exam, adding a new rule because of one student's selfish actions…
Everything Ailin had done, masquerading as Sōsuke Aizen, played out before Aizen's eyes. Twenty years of actions compressed into a few fleeting moments.
Ailin believed that even if Aizen hadn't actually done these things, after witnessing them, he would accept them as his own.
Aizen's understanding of human nature far exceeded Ailin's.
"Brilliant!"
"It seems I was right about you, Captain Ailin. You and I, we are the same."
"We are not like Kisuke Urahara, who clings to the status quo, blinded by foolish loyalty. If he wants to serve the Soul King, then let us be the ones to give him his final farewell!"
Having witnessed Ailin's actions, especially the Hollow created through his experiments, a Hollow possessing the combat instincts of a Shinigami, Aizen was deeply impressed.
That Hollow, born from the reishi of countless Hollowfied Shinigami, possessed both the powers of a Hollow and the combat instincts of a Shinigami. Its potential far exceeded that of any other Hollow Aizen had encountered in Hueco Mundo.
If he were to continue Ailin's research, to nurture that Hollow further, it would undoubtedly aid him in his own quest to transcend the limits of a Shinigami.
"No, Captain Aizen. We are not the same."
Seeing Aizen's insistence, Ailin raised a hand, interrupting him. He had only done these things to ensure the birth of Ichigo Kurosaki, the protagonist from his memories. It was his insurance policy, his guarantee against the Soul King's plans.
He hadn't expected Aizen to misinterpret his actions, believing they aligned with his own.
Sheathing Kyōka Suigetsu, Ailin tossed Aizen's Zanpakutō towards him.
"This is the first time I'm sparing you, Aizen. It will also be the last."
After Aizen had sheathed his Zanpakutō, Ailin continued…