"The Reiatsu disturbance just now was indeed Tenteikūra. So you already know what I did." Sōsuke Aizen showed no concern for the power Muten Natsu was gathering. "That's what I admire about you. Once you make a decision, you always strive to carry it out to the best of your ability. I noticed it back when you wanted to remain in the 4th Division but couldn't master Kaidō, so you came to me to learn how to handle paperwork. That was the first time I'd ever seen someone so talented at clerical work."
Muten Natsu kept his eyes fixed on Sōsuke Aizen, compressing his Reiatsu with great effort.
If given enough time to prepare, Muten Natsu could also instantly defeat Tōshirō Hitsugaya.
But Sōsuke Aizen had merely swung his sword casually, and Tōshirō Hitsugaya had already lost the ability to fight.
The gap between them was not small.
"It's a shame you're too lazy. You enjoy letting your ordinary life repeat itself day after day. If something happens that doesn't suit you, your first instinct is to pretend nothing happened." A trace of nostalgia appeared in Sōsuke Aizen's eyes behind his glasses. "Even when I repeatedly assigned you documents involving the darker side of Seireitei, you handled them like a machine, finishing them quickly and flawlessly. Then you'd act as if nothing had happened and go back to the 4th Division to ask Captain Unohana for praise."
Did something like that really happen?
Muten Natsu had no memory of it at all.
After all, when he was learning paperwork from Sōsuke Aizen, it was Myōki who had been doing the hard work.
"So I had no choice but to take certain necessary measures." Sōsuke Aizen turned his gaze toward Rukia Kuchiki. "For example... arranging for a Hollow to capture Rukia Kuchiki."
Rukia Kuchiki's thoughts drifted back several decades.
Among the three who had come out of Rukongai together, Renji Abarai had the best Zanjutsu scores, and Muten Natsu's draw technique was even more impressive. Only Rukia Kuchiki had the worst Zanjutsu scores.
Then Renji Abarai, who had just transferred to the 11th Division, suggested that everyone go there for training together.
As for the paperwork...
["Captain Aizen will take care of it!"]
Renji Abarai had a confident look that clearly said [Someone in my squad has connections]. Since he had previously served in the 5th Division, and Sōsuke Aizen was known for taking good care of his subordinates, no one felt anything was wrong at the time.
"Szayelaporro..." Rukia Kuchiki softly spoke the name of a Hollow.
After Rukia was captured and taken to Hueco Mundo, Muten Natsu, Renji Abarai, and Takuma followed her inside.
The leader of the Hollows hunting them in Hueco Mundo was Szayelaporro.
That escape had been incredibly dangerous. In the end, it was thanks to the intervention of a famous Shinigami who had entered Hueco Mundo years earlier, the assistance of a strange Hollow, and the pressure another powerful Hollow placed on Szayelaporro that the four of them managed to escape and return to Soul Society.
"Szayelaporro is a very useful subordinate. He successfully forced you to display far greater power than usual. And just as expected, when you returned to Soul Society, you were locked up in the Nest of Maggots." Sōsuke Aizen shook his head helplessly. "Unfortunately, Captain Unohana spoils you too much. She took you out the very next day."
Bloodshot veins spread through Muten Natsu's eyes. Of the two flame tails remaining behind him, one gradually grew shorter.
"This is where Takuma's help became necessary." Sōsuke Aizen's gaze deepened. "Muten, do you really understand Takuma?"
Muten Natsu said nothing, but the Reiatsu around him trembled uncontrollably.
"Why did he go out of his way to look after you at the Shin'ō Academy? Why did he join the 11th Division instead of the 6th after graduation? And why... did he die?"
Sōsuke Aizen answered his own questions.
"He approached you because of his family's orders. But during the time he spent with you, he ended up disobeying those orders. At the same time, he didn't want to betray the family that raised him, so he joined the 11th Division and devoted himself to fighting Hollows as a way of repaying them. However, your performance in Hueco Mundo reignited his family's interest. They secretly began planning to bring you back into the family. Takuma discovered this, and that was why he was silenced."
"Don't be stupid." Muten Natsu's voice was low. "After you've deceived so many people, you think I'd still believe your nonsense?"
"I'm not trying to excuse myself with lies." Sōsuke Aizen let out a soft laugh. "After all, the one who helped him discover his family's plan, and the one who made his family realize he had discovered it, was me."
A violent Reiatsu crushed down on the ground, splitting earth and stone apart.
Muten Natsu took a deep breath, barely managing to suppress the Reiatsu that was on the verge of erupting.
"A wise decision. When facing a powerful enemy, never let your emotions cloud your judgment." Sōsuke Aizen praised him with clear satisfaction. "Just as I expected, the death of your friend pushed you to act, and you managed to uncover part of the truth. However, there was one variable..."
Ganju Shiba noticed Sōsuke Aizen's gaze shift toward him, and a sudden sense of dread rose in his chest.
"Kaien Shiba actually managed to discover some information about me. That carefree man happened to possess intuition far beyond ordinary people." Sōsuke Aizen shook his head. "So I had no choice but to release the Hollow I had just successfully developed. A Hollow that can make a Zanpakutō disappear with a single touch, and one capable of merging with a Shinigami."
"You bastard!!!" Ganju Shiba drew the blade at his waist, but Ichigo Kurosaki grabbed him firmly.
This was absolutely not the time to act on impulse.
"That's right, don't be reckless." Sōsuke Aizen nodded approvingly at Ichigo Kurosaki's reaction. "Your mission is already complete. Now you only need to listen quietly."
Uryū Ishida immediately caught the key word in his sentence.
"Mission?"
"Exactly. West Rukongai is Kisuke Urahara's base of operations. The Senkaimon he can create can only open into West Rukongai. After I lowered the Seireitei barrier, all you had to do was use Kūkaku Shiba's Kakaku Taihō to break in from West Rukongai and draw the Shinigami's attention." Sōsuke Aizen explained everything patiently, like a careful teacher.
"You all performed very well. After I staged my death, it made things much easier for me to act."
"Sōsuke Aizen..." Rukia Kuchiki demanded, "What exactly are you trying to do?!"
"It seems Kisuke Urahara didn't tell you anything." Sōsuke Aizen spoke slowly. "Since we're at the end anyway, I'll clear up your doubts one last time."
Completely ignoring Muten Natsu's threatening presence, Sōsuke Aizen raised four fingers.
"A Shinigami has four basic methods of combat: Zanjutsu, Hakuda, Shunpo, and Kidō. Each of them has what can be called a limit to its strength. No matter how powerful a particular ability becomes, a Shinigami will eventually reach the limit of their soul's strength, creating a bottleneck that prevents any further growth."
"In other words, that is the limit of a Shinigami."