Aizen, Welcome to My World!  

It was clear that someone had deliberately kept Baishin in the dark about Azashiro's removal from the position of captain.

With Kyōka Suigetsu's ability, Aizen could easily manipulate Baishin's perception, making him see and hear whatever he desired.

Ailin even suspected that Aizen had manipulated Baishin's hearing, making him believe that the voices of others were informing him of Azashiro's presence within the Eleventh Division barracks, prompting him to attack at a time when both Ailin and Zaraki were absent.

If Aizen dared to manipulate someone into attacking the Eleventh Division and killing its members today, what would stop him from doing the same to the Kuchiki clan tomorrow, putting Haruko's safety at risk?

"Aizen, why can't you just focus on your own plans, cultivate Ichigo Kurosaki, and then accept your fate of being sealed within the Muken?" Ailin thought, his anger simmering. "Why do you insist on provoking me? Your abilities and ambitions are too dangerous. To protect those I care about, I must eliminate you."

Having made his decision, Ailin would not hesitate.

A golden spatial distortion appeared beside him, and his reiatsu flowed into the Zanpakutō within.

"Split – Shadow Blade!"

A green light emanated from the Zanpakutō as Ailin called out its name.

He swung the blade towards his left arm.

With a clean slice, his left arm detached from his shoulder. However, no blood flowed from the wound.

The severed arm, under Ailin's control, transformed into a perfect replica of himself.

This clone, however, possessed significantly less reiatsu than the original.

Shadow Blade was a Zanpakutō that Ailin had created based on the Shadow Clone Jutsu from another world.

However, perhaps due to his incomplete understanding of the concept of "cloning," the Zanpakutō's ability manifested as the transformation of severed limbs into clones, rather than the creation of independent copies.

The strength of the clone was determined by the amount of reiatsu contained within the severed limb.

If a hundred-year captain-level opponent were to be struck by Ailin's blade, the severed limb would transform into a clone with the strength of a peak captain-level Shinigami.

While this increased the number of opponents, it also significantly reduced their individual threat level.

After all, fighting two captain-level opponents was far easier than facing a single hundred-year captain.

Furthermore, there was no limit to how many times Ailin could use this ability.

With a few hundred slashes, even a hundred-year captain could be reduced to a swarm of weaker opponents, their strength diminished to the level of elite Shinigami or seated officers.

In a way, this Zanpakutō's ability was quite "overpowered."

The clone created from Ailin's left arm possessed the reiatsu of a hundred-year captain.

After instructing the clone to remain at the Kuchiki Manor and maintain his appearance, Ailin suppressed his own reiatsu and transformed into a shadow, heading towards the Fifth Division's barracks.

…

The Fifth Division served as the "Rescue Squad" within the Gotei 13. They were responsible for providing support to any division facing threats that exceeded their own capabilities or required immediate assistance.

Therefore, the Fifth Division was arguably the busiest division within the Gotei 13, rivaling even the Eighth Division in terms of workload.

The Eighth Division was tasked with gathering and analyzing information from various sources, then assigning missions to other divisions based on their findings.

The Fifth Division often received rescue requests from the Eighth Division's intelligence unit.

As a result, it was not uncommon to find the lights burning brightly within the Fifth Division's captain's quarters late into the night.

Captain Aizen diligently reviewed reports and assigned appropriate missions to his subordinates, ensuring their safety by matching their skills and abilities to the tasks at hand.

Since Aizen had assumed the role of captain, casualties within the Fifth Division during rescue missions had significantly decreased.

This was one of the reasons why Aizen was so popular among his subordinates.

With Ailin's abilities, infiltrating the Fifth Division's barracks undetected was effortless. Even Aizen himself couldn't perceive his presence.

Ailin entered Aizen's office and stood behind him.

He placed a hand on Aizen's shoulder, causing his brush to tremble and leave a blot of ink on the paper he was writing on.

"Oh? Captain Ailin," Aizen greeted him with his signature smile, setting his brush aside and turning to face his unexpected visitor. "To what do I owe the pleasure of your visit at this late hour?"

"Captain Aizen, it seems you haven't taken my words to heart. I told you that I have no interest in the current you. When you reach a level that piques my interest, I will come to strike you down. And when I deem you no longer useful, I will also come to claim your life."

Aizen's expression remained unchanged despite the threat.

"Captain Ailin, there's no denying that you have the power to make such claims," Aizen acknowledged. "However… How do you know I haven't been anticipating this moment?"

Aizen calmly organized the documents on his desk as he explained his plan.

"After witnessing your strength in the Rukongai, I realized that I could not defeat you with my current abilities. Furthermore, the difference in our reiatsu seems to render my Zanpakutō's ability ineffective against you."

As he spoke, Aizen touched the two healed wounds on his chest and abdomen.

That night, he had used Kyōka Suigetsu to manipulate the senses of everyone present, including Captain-Commander Yamamoto.

However, the moment Ailin used Shunpo to appear behind him, Aizen knew that his ability had no effect on him.

For Aizen, who viewed the entire Seireitei as his personal laboratory, Ailin's immunity to Kyōka Suigetsu made him an unpredictable variable.

Over the years, Aizen had conducted tens of thousands of experiments in Hueco Mundo using the Hōgyoku, successfully transforming Gillian-class and higher-level Hollows into Shinigami-like beings known as Arrancar.

However, his research on "Shinigami Hollowfication" had stagnated, showing no progress compared to decades ago.

To gather more data and perfect his experiments, Aizen planned to unleash Hollows upon Soul Society, allowing them to devour or possess Shinigami to achieve Hollowfication.

But for this plan to succeed, there could be no individuals within the Seireitei who were immune to Kyōka Suigetsu's control.

Unfortunately, even with his reiatsu reaching the limits of a Shinigami thanks to the Hōgyoku, Aizen wasn't confident in his ability to manipulate Ailin's senses.

Therefore, he had decided to eliminate Ailin from the Seireitei before commencing his experiments.

The Baishin incident was merely a test, an attempt to drive Ailin away.

However, Aizen hadn't anticipated Ailin seeking him out so soon after dealing with Baishin.

"Since I cannot defeat you, Captain Ailin, I will simply have to find someone who can," Aizen said, his hand resting on the hilt of his Zanpakutō.

All he needed to do was use Kyōka Suigetsu to manipulate the perceptions of the hypnotized Shinigami, making them witness a fabricated scene of Captain Ailin attacking him.

Soon, Captain-Commander Yamamoto would arrive at the Fifth Division barracks, only to find Ailin attempting to kill him.

"I don't know what you're planning, but… Without us in the Seireitei, how many of your plans will come to fruition?" Ailin's voice echoed behind Aizen.

"Bankai – Unlimited Blade Works!"

After years of training, Ailin's control over his reiatsu had reached an unparalleled level.

The surge of spiritual pressure released by his Bankai was completely contained within his body, not a single trace leaking outwards.

Aizen's vision blurred for a moment.

When his sight returned, Ailin's voice, cold and menacing, echoed in his ears.

"Sōsuke Aizen, welcome to my world..."

…

That night, dark clouds obscured the moon over the Seireitei. A fierce wind howled, and a sense of unease settled upon the Shinigami. The entire Soul Society felt as if it were on the verge of collapse.

"Is this... the wrath of the Soul King?"

Jushiro Ukitake, captain of the Thirteenth Division, looked up at the sky with anxiety in his eyes.

"What has happened? Why is the Soul King so enraged? Could it be that something has changed in the future, prompting the Soul King to consider destroying the world?"

The leaders of the Five Great Noble Houses simultaneously looked towards the sky.

They could almost see the silhouette of the being imprisoned within the crystal, his fury growing.

Was the Soul King about to break free from his seal and cleanse the world of its impurities?

"Who has angered the Soul King?"

Shunsui Kyoraku, captain of the Eighth Division, reached for a Zanpakutō hidden within his robes.

If such an event were to occur, he would have no choice but to betray the wishes of Nanao Ise's mother and entrust the blade to her daughter.