Naraku Sora's expression was rather strange.
For a moment, he couldn't even tell if it was a good thing or a bad thing.
What did it mean that the ultimate profound mystery of Kaidō was the Impure World Reincarnation?
Did this really fit the setting?
The moment the light screen dissipated, wondrous knowledge continuously surged from the depths of his soul.
Countless science-related concepts intertwined and merged, transforming into a magical thing called inspiration that burst forth wildly in his mind.
Ultimately, it all coalesced into a single entity, forming a technique named [Impure World Reincarnation].
Compared to the high-end combat techniques from a certain neighboring sorcery school, the principles of the Impure World Reincarnation were undoubtedly much more complex. Because he had only grasped the basics, Naraku Sora couldn't guarantee a hundred percent success rate.
The essence of the ability hadn't changed much from his understanding of it.
It forcefully pulled a soul back from the pure land of the afterlife, then injected it into a prepared vessel, covering a living person's body with dirt and dust to take on the appearance the deceased had in life.
At the same time, it required a piece of the deceased's flesh as a catalyst.
Its main feature was defying the world's underlying logic and violating the natural laws of operation.
Naraku Sora thought about it carefully; it seemed he didn't really have anyone he wanted to resurrect.
Everyone he cared about was still alive and well.
Despite Old Man Yama's advanced age—an old geezer who had lived for who knew how many thousands of years—judging by his strength, the old man could easily live for at least another two thousand years.
Furthermore, given Yamamoto's personality, he probably wouldn't be willing to live on in the state of Impure World Reincarnation anyway.
Unless, of course, there was something in the Soul Society that the old man couldn't let go of.
Naraku Sora pondered it again and figured there probably wasn't.
With a disciple like him around, the Soul Society was safe and sound. Everyone lived happily together, so there was nothing to constantly worry about.
In that case, the Impure World Reincarnation seemed rather useless.
He decided to set it aside for now. When he returned to the Soul Society, he would ask Aizen if there was anyone he wanted to resurrect and conveniently help him out.
It would be best if it were his parents or something similar. Once they were resurrected, Sora could become sworn brothers with them, making his title as Aizen's adoptive son perfectly justifiable.
Inside the cell, Unohana Retsu looked at Naraku Sora with a hint of confusion.
Even though nothing had happened, his expression was constantly changing—joy, shock, contemplation, daydreaming, smugness...
*Did this child suffer some kind of aftereffect from our battle just now?*
At this thought, Unohana Retsu couldn't help but feel a bit worried.
According to her research, High-Speed Regeneration could heal injuries, but it couldn't cure illnesses. In the history of the Soul Society, countless powerful Soul Reapers had fallen to disease.
*I should give Sora a physical examination later.*
Unohana Retsu secretly made up her mind.
Such a beautiful fruit couldn't be allowed to wither away from some unknown illness.
She had finally abandoned her desire to die, and there was still a long future ahead. A single ultimate deathmatch wasn't nearly enough to satisfy her.
"Big Sis Retsu, do you think the dead can be brought back to life?"
Naraku Sora suddenly realized that he had a master of Kaidō right beside him.
Unohana Retsu paused for a moment. After instinctively thinking it over for a few seconds, she answered seriously:
"Under normal circumstances, it's impossible."
"However, if it's a human in the World of the Living, within the first few seconds of their death, Artificial Soul technology can be used to forcefully anchor the soul within the deceased body, thereby achieving resurrection."
"But this state is extremely unstable. The slightest external stimulus could cause the soul and body to separate again, or even trigger far more severe consequences."
Naraku Sora nodded thoughtfully.
He had some impression of Artificial Soul technology. He had heard Urahara Kisuke mention it in passing before, though it seemed Central 46 had banned it many years ago because it was deemed too dangerous.
However, he had heard that this technology had somewhat inspired Kirio Hikifune.
The Artificial Soul project she was currently researching was somewhat related to it.
Unohana Retsu paused for a moment before continuing:
"Furthermore, as far as I know, there are historical records of the dead being resurrected. Whether it was due to a Zanpakutō ability or some unknown technology, however, remains a mystery."
"Why are you suddenly asking about this?"
Naraku Sora opened the cell door, letting Unohana Retsu out.
"It just crossed my mind, that's all."
It wasn't that he didn't trust Unohana Retsu, but rather that some things were better kept secret from her.
Although she was inherently a rebellious figure, there was still a distinct difference between her and people like Aizen.
Long before meeting him, Aizen had already begun attempting to touch upon the true nature of the three realms.
After they became close friends, Aizen had even set his sights on the Spirit King and the Zero Division.
That could no longer be described as merely rebellious; it was pure anti-world behavior.
As for Urahara Kisuke, although he was willing to live under the rules, he had actually still taken corresponding remedial measures.
Like creating a backup Spirit King, for instance.
Of course, that was all a matter for the future.
Unohana Retsu looked at Naraku Sora's peaceful expression and didn't press the issue.
In her eyes, a man who had accomplished something as monumental as ruling Hueco Mundo was bound to do shocking things, and it was only natural.
Even if he were to replace the Spirit King...
Well, maybe that was still a bit beyond her acceptable limits.
"I noticed that the overall architectural style of Las Noches is extremely similar to the Shino Prison barracks. I wonder, did you happen to install a Hell Hot Spring?"
Unohana Retsu asked softly, suddenly thinking of something.
"I did, I did."
Naraku Sora realized what she meant. "The Hell Hot Spring is also very effective for Arrancars who aren't adept at High-Speed Regeneration. Plus, since martial virtue is highly valued around here, it gets used quite frequently."
"Follow me."
The two left the prison and soon arrived near two steaming hot springs, one red and one white.
Unohana Retsu approached the rock wall and reached out to test the water. A warm sensation flowed from her right fingertips into her body, instantly invigorating her residual spiritual power.
Some of the injuries caused by her Bankai being shattered began to heal at a visible rate.
"The effects are even stronger than the ones at the Comprehensive Relief Clinic."
Unohana Retsu lowered her gaze, a flash of surprise in her eyes.
As she spoke, she briskly took off her tattered Captain's haori and untied the light-colored sash around her waist. A dazzling flash of white skin slipped through the hot spring's mist, and with a splash, she submerged herself in the water.
She seemed completely unbothered by the fact that someone else was standing right there.
Her movements were so swift that even Naraku Sora was momentarily stunned.
Why were all the female Soul Reapers he knew so unreserved?
Through the thin mist, in the direction of the splashing water, he could vaguely make out massive curves floating on the surface, with two hands resting upon them, pressing down gently.
Feeling the warmth seeping in from the outside and her Reiatsu continuously recovering, Unohana Retsu felt completely relaxed in both body and mind. She leaned lazily against the rock wall.
Soaking in a hot spring after an all-out deathmatch truly was a heavenly delight.
After soaking for a few seconds, she suddenly thought of something. She flashed a teasing smile at the shore, her voice echoing softly like a devil's whisper:
"Sora, aren't you going to join me?"
"?"
Naraku Sora's expression instantly turned solemn.
Although it was a bit fast, wouldn't he be worse than a beast if he refused at a time like this?
He quickly stripped off his clothes in a few swift motions and stepped forward, submerging himself directly into the hot spring. A pale figure slowly approached him.
The hazy mist could no longer obscure his vision, and the beautiful scenery was now in full view.
Unohana Retsu's braided hair had come undone, floating on the surface of the water.
Initially, she had been covering herself slightly, but as she drew closer, she released her hands and pressed them against Naraku Sora's skin instead, feeling the dormant, scorching heat within him.
It was like a volcano on the verge of erupting.
"Sora, the act of pleasing is inherently mutual..."
Unohana Retsu leaned close to his ear, her gentle voice brushing past like a babbling brook.
"So, isn't there anything you want to do?"
Since she had already put it like that, he wouldn't even deserve to be called a man if he backed down now. It wasn't exactly a natural progression of things, but there was at least some emotional buildup.
In the past, after their Zanjutsu sparring sessions, he had always rested on her lap.
Today, since he had finally won, he might as well find somewhere else to rest.
Naraku Sora opened his arms and pulled her warm, soft body into his embrace. Feeling her smooth, jade-like skin, he lowered his head and kissed her.
As their eyes met, a nameless fire ignited in their hearts.
With a muffled groan as the starting point, an endless conquest began.
Leaving the residential palace feeling thoroughly refreshed, Naraku Sora stretched his body, his joints popping with crisp cracks.
Gazing up at the blue sky and white clouds, he felt a wave of physical and mental comfort wash over him.
To be honest, she truly lived up to her title as one of the strongest female Soul Reapers.
Unohana Retsu's talents, whether in the realm of combat or other areas, were absolutely top-tier.
Perhaps it was due to her persistent Zanjutsu training, or maybe she just knew how to take care of herself, but both her flexibility and endurance were outrageously strong.
Coupled with her immense Reiatsu, even with his extraordinary natural gifts, it had still taken him quite a bit of effort and a grueling, hard-fought battle to completely defeat her.
Recalling the battle just now, Naraku Sora grinned, revealing a contented smile.
His beautiful life was only just beginning!
Unohana Retsu rested in Las Noches for a few days before her Reiatsu was fully restored.
Sora had originally planned to have her stay a little longer, but considering she had left behind a suicide note before coming, he was worried it might cause some chaos.
He had no choice but to let her go back.
However, before she left, Grimmjow—whose head was entirely filled with the thrill of battle—challenged her once again.
In his mind, anyone who could fight Naraku Sora and survive was undoubtedly a powerhouse.
And what kind of powerhouse would shy away from a fight?
In response, Unohana Retsu glanced at Naraku Sora. Realizing he had no objections, she gladly accepted the challenge.
She was also quite curious about these Arrancars who had been modified from Menos Grande.
For a Menos Grande to actually accept the power of a Soul Reaper and transform into a state similar to one, there had to be countless secrets involved.
Even though Unohana Retsu wasn't a true researcher, she could still perceive the difficulty of such a feat.
She just hadn't expected Naraku Sora to possess such a high level of expertise in scientific research.
It was truly surprising.
Soon, the group arrived at the boundless desert outside Las Noches.