Admittedly, upon hearing Naraku Sora's words, Yamamoto subconsciously visualized himself undergoing Hollowfication for a fleeting moment.
To be honest, it was indeed quite tempting.
However, he quickly cast the thought aside.
He had borne the title of the Soul Society's strongest Soul Reaper for a thousand years. He was a symbol of this era, shouldering the final glory of the Soul Reapers.
How could such an existence abandon the ultimate honor of a Soul Reaper?
As a remnant of the old era, he naturally had his own convictions and pride in his heart.
If he wanted to become stronger, he needed to train diligently and stake everything on it.
Relying on the power of a Hollow meant he could no longer be called a Soul Reaper.
At this thought, Yamamoto's expression grew resolute once more. Just as he was about to speak, Naraku Sora suddenly interrupted him.
"Master, you'd better think carefully before you answer."
"If you cast aside your loyal subordinates, your former comrades, and even the entire Soul Society all for the sake of some trivial, so-called honor..."
"...then you're no different from Yhwach."
Hearing this, Yamamoto's breath hitched.
The words that had been on the tip of his tongue were completely caught in his throat.
Naraku Sora grinned. Squatting by the stove, he fiddled with Vajrayati, not forgetting to casually pull out Yamamoto's Ryūjin Jakka as well.
One for roasting sweet potatoes, the other for boiling tea.
It had to be said, as the strongest fire-type Zanpakutō, it truly possessed a unique advantage when it came to brewing tea.
The moment he gripped the hilt, he could clearly sense the terrifying power hidden within, as if it could destroy the entire world.
Perhaps because he had been slashed by it so often, Ryūjin Jakka was quite familiar with Naraku Sora's Reiatsu. Coupled with Yamamoto's tacit approval from the sidelines, using it to boil some tea was perfectly fine.
Humming an unknown tune, Naraku Sora let the fragrance of the tea mix with the sweetness of the sweet potatoes, wafting through the courtyard.
Beside him, Yamamoto wore a conflicted expression, seemingly caught in a dilemma.
Having studied under Yamamoto for so long, Naraku Sora was naturally the person who understood this old man best in the entire world.
In the past, he had been a Demon of the Sword who would use any means necessary to crush his enemies, even treating his own subordinates as mere specks of dust.
Later, after the war with the Quincy ended, the things he wanted to protect in his heart increased.
But at the same time, this made his personality pedantic and stubborn. For the sake of the Soul Society's order, he was even willing to restrict his own power.
This also resulted in the nobles becoming difficult to restrain by the law, growing increasingly lawless.
Truthfully, Naraku Sora found this mindset somewhat hard to comprehend.
It was just like Madarame Ikkaku in the original timeline, who kept his Bankai hidden just so he could continue following Zaraki Kenpachi.
This led to his defeat during the battle in Karakura Town when he fought Choe Neng Poww to protect the boundary pillars. Because he refused to reveal his Bankai, he was crushed, forcing Komamura to step in and save the day.
In Naraku Sora's eyes, such behavior was the pinnacle of stupidity.
The same went for the future Yamamoto, who remained one-armed simply because he didn't want to rely on Inoue Orihime's power.
His reason for doing so was merely to uphold his so-called principles.
Utterly foolish.
Fortunately, after so many years of his influence, Yamamoto's tolerance threshold was much higher than before.
If it had been the Yamamoto of the past, seeing him undergo Hollowfication would have probably caused the old man to fly into a rage.
There was no way they could sit together like this, enjoying the peace and tranquility between master and disciple.
Therefore, in Naraku Sora's view, getting Yamamoto to change his mind was still entirely possible.
"..."
Yamamoto raised his gaze, looking at Naraku Sora who was happily busying himself. His eyes held an indescribable emotion, as if he had just made a decision that went against his original intentions.
"If I fail during the Hollowfication process, the duty of the Gotei will be entrusted to you."
Naraku Sora raised an eyebrow, not expecting Yamamoto to say such a thing.
It seemed that making this decision had indeed required a great deal of resolve.
However, Naraku Sora had absolutely no interest in that whatsoever.
Acting as the substitute Head Captain for a few days was more than enough. The Gotei 13 was full of slackers; how could they compare to his New 13 Squads?
He didn't have to worry about squad duties at all; he just needed to focus on himself.
Being the Head Captain was nothing special.
Seemingly catching the flash of disdain in a certain someone's eyes, Yamamoto's eye twitched violently, his blood pressure spiking.
*This rebellious disciple is an absolute bastard!*
Aizen had been in a good mood lately.
The recent Reigai rebellion had yielded a bountiful harvest.
Inside the laboratory, a massive incubation tank stood in the center of the floor, filled with a large amount of viscous green liquid.
Inaba Kagerōza floated within it, his eyes tightly shut, seemingly having completely lost consciousness.
Various instruments were connected to his body, constantly monitoring his condition—from his physical body to his Reiatsu, and even his soul was not spared.
Just in case, Sekki-seki powder had been added during the tank's construction, which could greatly suppress a Soul Reaper's spiritual power.
Furthermore, the green liquid contained a large amount of sedative components, keeping Inaba Kagerōza in a constant comatose state.
Other Captain-level materials did not receive this kind of special treatment.
The reason he was treated with such caution was that Inaba Kagerōza's body contained fragments suspected to be the "Soul King's Chain."
Aizen pushed up the glasses on the bridge of his nose, his expression focused as he calculated various data, analyzing the power components and specific properties contained within the fragments.
Aside from Inaba Kagerōza himself, a massive amount of research data related to Soul Reaper souls had also been discovered in his laboratory.
Although much of the content overlapped with Aizen's own research, there was a small portion of data that had never been discovered before.
Aizen immersed himself in scientific research, enjoying the beauty of deciphering the unknown.
His mood was exceptionally cheerful.
After an unknown amount of time, he looked up out the window. The sun was setting, its afterglow falling between the shade of the trees. A wonderful day had already come to an end.
As expected, good times always passed quickly.
The corners of Aizen's mouth curled up slightly as he prepared to wrap up his research for the day.
The next second, a voice that sent his blood pressure soaring suddenly barged into the laboratory.
"Sōsuke-emon, please help me!!"
Aizen's smile froze.
Under his extremely resistant gaze, a certain walking disaster violently pushed open the laboratory doors and barged straight in.
Looking at the metal doors that were nearly scrapped in a single strike, Aizen couldn't help but feel a headache coming on.
"You are an existence on the same level as a Captain now. What kind of decency is this, acting so recklessly all day?"
"Is this all you've learned?"
Hearing this, Naraku Sora paused for a second and subconsciously retorted,
"You don't actually think Old Man Yama is steady, do you?"
Aizen fell silent.
*I almost forgot. Recklessness is practically a tradition of their Genryū style.*
"Speak. What happened this time?"
Aizen stored away the incubation tank containing Inaba Kagerōza, then sat down on a nearby seat. He picked up a prepared teapot and poured two cups of black tea.
Naraku Sora immediately recounted his conversation with Yamamoto in detail.
After listening, Aizen gave him a deep look and spoke with a hint of gratification,
"Getting Head Captain Yamamoto to change his mind is indeed no easy feat."
"This also indirectly proves how much he values you as his disciple. Perhaps your status in his heart has already surpassed that of Captain Kyōraku and Captain Ukitake."
"As for the success rate of the Hollowfication experiment you're concerned about, it actually depends more on Head Captain Yamamoto himself."
Aizen touched the control console, causing it to automatically fold and merge. Accompanied by the sound of grinding metal, it sank completely into the floor.
"Before the experiment truly begins, we might as well make some other preparations."
"After all—"
"The space required for the Hollowfication of the Soul Society's strongest Soul Reaper is by no means a small scale."
A crescent moon hung high in the sky.
The void shattered, revealing a pitch-black expanse. An elderly figure stepped out from the Garganta, adding a touch of heat to the dark and cold Hueco Mundo.
Glancing at the Garganta slowly closing behind him, Yamamoto's emotions were complicated to the extreme.
Having lived for thousands of years, this was his first time coming to Hueco Mundo in such a manner.
Ever since taking on the role of Head Captain of the Gotei 13, he had never been here again, though he had read plenty of intelligence reports regarding Hueco Mundo.
In the early years, the Gotei 13 had even organized Hueco Mundo subjugation forces to explore the area.
However, due to severe casualties and extremely low efficiency, they eventually abandoned the effort.
Now, arriving in Hueco Mundo as a guest made Yamamoto feel rather unaccustomed.
Even though his rebellious disciple had repeatedly emphasized to treat this place like his own home, he still felt incredibly out of place.
*Can Hollows and Soul Reapers truly coexist peacefully?*
Yamamoto gazed into the distance. A majestic palace, resembling a mountain range, stood upon the boundless desert, looking almost like a miracle.
A structure of such scale could not be seen anywhere in the Soul Society.
As everyone knew, Hollows were often associated with cruelty and tyranny, typically acting on pure instinct.
They rarely gathered together, let alone built such a massive palace.
*Could it be that all of this is Naraku Sora's doing?*
Yamamoto couldn't help but glance at the young man beside him, his gaze somewhat subtle.
Soon, the two appeared before the main gates of Las Noches.
The first thing that caught his eye was a dense, overwhelming formation of Gillian, covering all the desert within sight like heavy, dark clouds.
Under the mandatory orders of the Arrancar, the chaotic instincts of the Gillian were suppressed.
In addition, there were perfectly synchronized formations of Arrancar.
Long ago, when the Arrancarification technology was perfected, any Menos Grande in Las Noches that met the qualifications—whether Gillian or Adjuchas—had completed their Arrancarification.
In terms of mid-level combat power, Hueco Mundo had already far surpassed the Soul Society.
"Welcome to Las Noches, Head Captain Yamamoto!"
Their overlapping voices were deafening, soaring straight into the clouds.
Yamamoto's face was filled with astonishment, unable to recover his senses for a moment.
Although he had mentally prepared himself before coming, seeing this exaggerated scene still inevitably left him shocked by the sight before him.
*To think that this rebellious disciple, who never takes anything seriously, has quietly built such an empire in Hueco Mundo.*
*Compared to my own achievements in the Soul Society, this is equal, if not greater.*
At this thought, Yamamoto felt deeply gratified.
*Since Naraku Sora can manage Hueco Mundo so flawlessly, surely when he inherits the position of Head Captain in the future, he will do an even more perfect job than I have.*
After thoroughly showing off to Yamamoto, Naraku Sora led the old man formally through the gates.
"Welcome to my..."
"...Las Noches!"