Reborn into Naruto World with Tenseigan

Excluding Rikudo Sennin’s Rinnegan, there have been only one and a half pairs of Rinnegan in the Shinobi World, canonically speaking.

And in the one-and-a-half pair of Rinnegan, Uchiha Sasuke’s Rinnegan was also evolved because Rikudo Sennin gave him the Yin part of his own Chakra, so in a way, it wasn’t awakened by Sasuke himself, rather it was a given to him by Rikudo Sennin to prevent the revival of Kaguya, so it can not be used as an object of reference by Kuroto, because this method is extremely difficult to copy.

As such, Uchiha Madara’s method of awakening the Rinnegan is worth Kuroto’s research.

Uchiha Madara’s Rinnegan is the product of the fusion of Yin Chakra of Eternal Mangekyou Sharingan, and Yang Chakra of the implanted Hashirama Cells in his body.

In other words, if we use Madara’s Rinnegan as an example, the fusion of Yin Chakra of Eternal Mangekyou Sharingan and Yang Chakra from Hashirama Cells can theoretically result in the birth of Rinnegan.

Moreover, in the canon, Orochimaru and Yakushi Kabuto hypothesized that the Rinnegan can be awakened by combining Uchiha and Senju DNA. To that end, Kabuto successfully recreated the Rinnegan by infusing Hashirama Cells in Madara’s reincarnated body.

But considering that Uchiha Madara was the reincarnation of Otsutsuki Indra, at the same time, Senju Hashirama was the reincarnation of Otsutsuki Asura, so after implanting Hashirama Cells, Madara had access to both Indra and Asura’s Chakra, and the combination of Indra and Asura’s Chakra allowed him to obtain Hagoromo’s own chakra thus he awakened the Rinnegan.

If we keep both the conjectures in mind, then a question arises here, whether combining the Chakra of Indra and Asura to give birth to Hagoromo’s Chakra is necessary or not to evolve a pair of Rinnegan? Kuroto’s objective is to figure out this problem using this Implantation Operation.

Kuroto wants to understand whether Obtaining Hagoromo’s Chakra is the only condition to awakening the Rinnegan or is it just one of the many ways.

If Hagoromo’s Chakra is not the only necessary condition, then Kuroto has the confidence in cultivating a pair of Rinnegan.

But if Hagoromo’s Chakra is the only necessary condition, then Kuroto will have to involve Uchiha Sasuke too in his research because Sasuke is the reincarnation of Indra.

With the objective of figuring out this problem, Kuroto started Shisui’s implantation Operation.

After attaching all the devices to keep monitoring Shisui’s vital signs all time, Kuroto disinfected the surgical instruments, then calmly replaced Shisui’s eyes with the Eternal Mangekyou.

A few seconds after the eyes were implanted in Shisui’s sockets, Kuroto asked, “How do you feel?”

After adjusting to the returned vision, Shisui observed the surroundings for a while, then said with a doubtful tone, “I am not sure why, but these eyes are giving me a very familiar sensation, and there is no resistance, as if these are no foreign body part, rather they have been part of my body.”

Kuroto nodded with a smile upon hearing Shisui’s doubts, “That’s good then.”

Uchiha Ryota’s Eternal Mangekyou Sharingan has been washed and nurtured by the Chakra of Tsukihi Clone for quite a few years already and has a high acceptance of Tsukihi Clone’s Chakra.

Tsukihi Clone is a fusion of Kuroto’s and Shisui’s Cells, the gender of the resultant clone may have changed due to female gender determining genes being dominant, but this doesn’t change the fact that Tsukihi Clone’s Chakra is quite similar to that of Shisui’s own Chakra, as such it is only natural that these eyes have a high acceptance rate of Shisui’s Chakra.

While Shisui got more and more familiar with the Eternal Mangekyou Sharingan, Kuroto monitored the slight changes in his vital signs, and said, “The Cell activator is in full effects, the activity of the cells in your body has increased by 17%, and is still increasing which might be because of the implant of these eyes. Activate the Eternal Mangekyou Sharingan and let the Yin Chakra flow in your brain.”

Shisui nodded, closed his eyelids, then opened them, and this time, the black eyes in his sockets have changed into the Eternal Mangekyou Sharingan.

Seeing that Shisui was able to perfectly activate those eyes, Kuroto nodded.

The first step of the operation was the replacement of eyes, which has been completed successfully, now comes the next step of injecting the Fusion Solution.

Fusion Solutions are quite unstable in nature, they can only remain stable for about an hour, after which they start to decompose, and the reaction of decomposition they generally follow is a zero-order reaction, with a half-life period of 5 minutes.

As such, they can not be kept in storage and must be prepared on sight.

So, Kuroto started the on-sight development of Fusion Solutions.

Since all the materials required were already prepared beforehand, as such, it only took about half an hour for Kuroto to prepare the Fusion Solution. After it was prepared, Kuroto transferred the Fusion Solution into an injector, and carrying the injector Kuroto walked towards the Operating Table.

After taking a reading of Shisui’s Vital Signs, especially his cell Activity and Body Temperature, Kuroto said, “Now I am going to inject the Fusion Solution, be prepared to feel the pain.”

Shisui nodded calmly.

Kuroto then injected the medicinal green color Fusion Solution inside Shisui’s Blood Stream.

As soon as, the Fusion Solution was injected inside Shisui’s blood Stream, all his veins bulged, and the dark green color veins were now visible to the naked eyes, it was as if something started to ferment in his body and the rate of transpiration increased again by 30%.

If it hadn’t been for a water dripper to have been attached to Shisui’s artery, he might have died due to dehydration.

Further, his heart rate increased to 240 beats per minute which are already past the dangerous levels even for a top-tier athlete, but he is a Shinobi, and Shinobi must endure and so did Shisui. Intense Pain raged in his body, it felt as if all his blood vessels will explode but Shisui only gritted his teeth and endured the burning pain.

Kuroto could see that Shisui is suffering from intense pain at this moment, but he didn’t say anything and proceeded with the third step.

From a small freezer, Kuroto took out two injectors along with a dozen small glass capsules that contained a cloudy-whitish liquid.

The cloudy-whitish liquid inside the glass capsules is the specially treated Hashirama Cells.

After placing the injectors and glass capsules on the side bench, Kuroto said to Shisui, “The effect of Fusion Solution will only last for a while, so the Cell Implantation must be carried out immediately, are you ready to face one of the most intense pains of your lifetime?”

Shisui chuckled with a ragged breath, “Kuroto-san, you really aren’t encouraging here.”

“You are right I suppose.” Kuroto nodded, then said, “Okay, so how about this?”

‘Transformation Jutsu!’

Poof!

Instantly, Kuroto transformed into a cute and sexy nurse with a big bust, and said to Shisui in an encouraging tone all while winking her left eye, “Ganbatte Kudasai Shisui-kun!”

“Cough-cough, that’s not funny Kuroto-san!” Shisui coughed in embarrassment, he was left speechless.

Kuroto chuckled then released the transformation, and asked, “Are you ready Shisui?” only this time, his tone was much more serious.

Shisui nodded, “Yes, I am.”

“Okay, so now I am injecting the Hashirama Cells.” With that said, Kuroto placed a capsule in the injector, then after taking a reading of all of Shisui’s Vital Signs, he started injecting Hashirama Cells, and while keeping his eyes on monitors, he said, “Do not forget to use the Visual Prowess to suppress Hashirama Cells from taking over your body, will power alone can not stop the erosion of Hashirama Cells.”

One by one, Kuroto started to inject all the 12 capsules into Shisui’s body. The reason for more than one capsule is because he has reduced the potency of Hashirama Cells quite a lot, at the same time, each capsule contains a specific gene-focused Solution, therefore, all 12 are necessary for perfect implantation.

Kuroto determined this segregation upon studying the Hashirama Cells with respect to his own genes and reached the conclusion that for the perfect implantation this method is currently the most suitable one.

By perfect implantation, Kuroto means no extra face or whiteness visible in the body, which is different from the Hashirama Cell Implantation of Madara, Obito, and Danzo.

In Kuroto’s view, their methods are quite crude, as such the result is not perfect, there are obviously visible traces of implantation of Hashirama cells. Shodaime-sama’s face is on Madara’s Chest, on Danzo’s shoulder, and on half of Obito’s White Zetsu-type body.

Their implantation methods were quite crude and only successful on a cellular level, or organ level, whereas, the implantation Operation, Kuroto is after is at the Genetic Level, only when the gene itself is altered, will the implantation operation will be successful, this is his opinion.

In the current Shinobi World, there are very few people capable of reaching such a level, currently, they only include him, Orochimaru, and Hiruko, at least, as per Kuroto’s understanding that is.

There might be a few others, but Kuroto is not yet aware of those.

By the time, the 12^th Capsule was being injected, Shisui was already writhing in pain, and this time the pain was so intense that even if he wanted to, he couldn’t help but shout and wail, “Argghhhh……”

‘Multi Shadow Clone Jutsu!’

Poof Poof Poof Poof Poof

“Hold him still!” Kuroto created five Shadow Clones to keep Shisui on the operation bed, as well as stuffed a piece of cloth in Shisui’s mouth to make sure that he doesn’t accidentally bite his tongue.

After completely injecting the 12^th Capsule, Kuroto put the Injector on the side and observed Shisui’s state with his Tenseigan.

He could see, the intense rise in cellular activity by more than 200% additional to the previous increase.

Shisui was struggling, and it took all five of Kuroto’s clones to keep Shisui’s body on the bed.

If it is said that Kuroto himself wasn’t nervous, then it would be a lie. Few things in the Shinobi World can make him nervous, and Shisui’s current state is one of them, in fact, Kuroto could even see some tree buds sprouting out of Shisui’s body and taking the form of a sapling if those buds continue to grow, then it would be very dangerous for Shisui.

But Kuroto can only watch and wait and let Shisui fight his way out, ‘Come on Shisui, I know you can do this.’