Research on Mangekyo

In the Otogakure of the Land of Sound.

Natsuki had previously provided Orochimaru with the research direction related to the evolution of the Sharingan.

This progression ranged from one tomoe to the regular mangekyo, showcasing a continuous enhancement of Yin Release Chakra.

The Eternal Mangekyo, in theory, aimed to complement the genes in the user's body, allowing it to withstand the ancestral strain of the mangekyo and prevent damage to the eyes during use.

However, Natsuki, having achieved the Eternal Mangekyo, seemed to have bypassed this step.

To assist Orochimaru in his experiments, Natsuki needed to showcase how the Eternal Mangekyo could be produced without the complementing gene.

Despite the golden finger's aid in creating the Eternal Mangekyo, Natsuki felt it would be beneficial to contribute to the experimentation process.

Upon learning of Natsuki's attainment of the Eternal Mangekyo, Orochimaru found it difficult to believe, but given Natsuki's ability to foresee the future, such extraordinary occurrences seemed within the realm of possibility.

Orochimaru promptly conducted various examinations, examining Natsuki's Susanoo and two different eye techniques.

Natsuki's Susanoo had reached a maximum size of one hundred meters and was still growing.

Additionally, the weapon-strengthening pupil technique, Tensouunryu, displayed an astonishing attack power that even impressed Orochimaru.

This technique could forcibly erase space, turning the cut area into instant nothingness.

When Orochimaru heard the name of this pupil technique, his expression took on a peculiar and intrigued look.

Opening his mouth, Orochimaru spat out a sharp sword, catching Natsuki's attention.

"Kusanagi sword?" Natsuki raised an eyebrow.

However, in this world, the Kusanagi sword isn't a specific sword but rather a style of sword.

Natsuki's Tensouunryu is a unique blend of pupil technique and chakra, forming weapons attached to Susanoo.

Orochimaru, too, possesses more than one Kusanagi sword due to his mastery of the art of Yamata no Orochi, where the Kusanagi sword is the weapon of the serpent deity.

In myth, each Kusanagi sword of Yamata no Orochi is represented as a snake, making Orochimaru's collection essentially limitless, though only a few are genuinely sharp.

Seizing the opportunity, Natsuki, knowing Orochimaru well, directly requested the Kusanagi sword.

"Just in time, I happened to want to bring back a gift for my apprentice. Orochimaru gave me a sword," Natsuki stated.

Orochimaru, unfazed, opened his mouth again and spat out another Kusanagi sword.

"This sword should be enough for Sasuke-kun," Orochimaru remarked with a smile.

Given his good relationship with Itachi, Orochimaru had no issues offering Sasuke a sword.

Natsuki secured the Kusanagi sword to his waist and prepared for the day's experiment.

His second eye technique, known as Kansatsu, primarily enhanced his observation abilities.

The more eye power he injected, the clearer his vision became.

However, Natsuki rarely used this technique, as it consumed a considerable amount of energy.

Orochimaru intended to test how long it would take for Natsuki's Eternal Mangekyo to recover after exhausting its eye power.

Kansatsu was the most suitable for this experiment. Natsuki activated his Eternal Mangekyo and began injecting pupil power into his eye.

As Natsuki's vision became clearer, he reached a point where it started to blur.

Wondering if he had reached the limit, he continued to input eye power.

Suddenly, the entire world seemed to open up, and the blurry scenery transformed into a different view.

"Bang!" Orochimaru used a nearby storage scroll, obtaining something Natsuki couldn't feel.

"Bang!" Orochimaru then utilized a psychic technique, attempting to gather information as usual.

Following the sound, Natsuki discovered a space channel opening where the psychic technique was employed.

In that space, numerous snakes were present, and a large white-scaled snake in a temple turned its attention towards him.

As Natsuki focused on the space passage, he realized that this eye technique could see through different spaces and trace the coordinates of space.

...

Ryūchi Cave.

The White Snake Sage adjusted the pipe he was holding, disturbed by the realization that someone had been peeking into the Cave.

The White Snake Sage contemplated silently, assessing the situation and foreseeing a future filled with chaos.

...

"This eye technique can see through different spaces and trace the coordinates of space," Natsuki explained.

Orochimaru was also impressed upon hearing this.

While such an ability might not be particularly advantageous in low-level battles, it presented a significant edge when dealing with time and space ninjutsu.

One of the most well-known time and space techniques is the Flying Thunder God jutsu.

This jutsu involves two main steps: first, determining the coordinates, and second, teleporting to the designated location.

If Natsuki were to face an opponent using the Flying Thunder God jutsu, he could discern the coordinates and predict the next move without actively searching for the technique.

Natsuki had a particular interest in Obito's Kamui ability.

Previously, he believed that he could only counter Obito's divine power, but with this newfound ability to see and trace spatial coordinates, Obito would have no place to hide in the present world.

...

After a few days, Orochimaru's analysis of Natsuki's Sharingan was complete.

Their initial hypothesis was that the Sharingan Yin Release and Yang Release were superimposed, linked by blood, and overlapping at the genetic level.

By addressing the deficiencies in the bloodline and completing a bloodline evolution, the Eternal Mangekyo was formed.

However, Orochimaru and Natsuki discovered that Natsuki's Eternal Mangekyo was a qualitative change that occurred naturally due to the extraordinarily powerful eyes.

It was similar to pouring unlimited water into a container with limited space, and the water naturally compressed as long as the container was strong enough.

As for why Natsuki's container (his eyes) was so resilient, Orochimaru had yet to unravel.

Natsuki's method of achieving the Eternal Mangekyo provided Orochimaru with new perspectives.

Shisui's eyes now had a second pathway to evolve into the Eternal Mangekyo.

However, Natsuki and Orochimaru still needed to discuss whether the Eternal Mangekyo had the potential for further evolution.

During this period, Natsuki also told Otsutsuki and the succeeding reincarnations of Indra and Asura.

With only one pair of Rinnegan in the ninja world, currently in Nagato's possession, there was no reference point.

Whether the Sharingan could evolve into the Rinnegan without the involvement of Indra Chakra remained uncertain.

Natsuki had Sasuke in mind, as he might be the only one capable of successfully evolving the Rinnegan if Indra and Asura's chakra proved necessary.

If this were the case, the relationship between the eternal Mangekyo and the Rinnegan could not be seen as a class relationship; the Rinnegan would be considered a variant of the eternal Mangekyo.