After instructing a Ninja Cat to deliver a message confirming his safety to Fugaku Uchiha, Uchiha Ensei decided to carry out his strength-enhancement experiment amid the ruins of the Empty Zone.
At this point in time, aside from the possibility of encountering the Ōtsutsuki Clan, Nagato was likely the strongest enemy Uchiha Ensei could face.
If Nagato's legs had not been healed, then the Six Paths of Pain alone would not pose much of a threat to him.
But now, Nagato's body had likely been fused with White Zetsu cells, and there was a strong chance that Kotoamatsukami had altered his thoughts.
More importantly, the Rinnegan was practically the natural counter to Uchiha Ensei's fighting style, which relied purely on overwhelming opponents with immense ocular power.
If he had not learned the Flying Thunder God in advance, he would probably have had no choice but to use some trump cards, such as Izanagi, his Sage Mode riddled with hidden dangers, and a whole series of other forbidden techniques with steep costs.
The level of danger involved in any technique that someone like Uchiha Ensei classified as forbidden was easy to imagine.
"I've decided. I need to find a way to awaken my Mangekyō Sharingan. It's the simplest and safest way to increase my strength."
"With the Mangekyō Sharingan, Susanoo can truly display its power instead of being so easily absorbed by the Preta Path."
From his long list of experimental plans, Uchiha Ensei selected what he considered the easiest one to begin.
However, before conducting the experiment to actively awaken the Mangekyō Sharingan, Uchiha Ensei still had much preparation to do.
For example, he needed to create a Hashirama Cells culture medium for the cloned One-Tomoe Sharingan, allowing them to develop into Three-Tomoe Sharingan in the shortest possible time.
After all, the stockpile of Three-Tomoe Sharingan from the Uchiha Clan that he had obtained from Fugaku Uchiha was nearly depleted.
Although he disliked such a slow cultivation method, Uchiha Ensei still had to make preparations, lest he need them someday and have no Three-Tomoe Sharingan left to use.
As a member of the Uchiha Clan, his own eyes were the most useful. Unless absolutely necessary, Uchiha Ensei would not abandon them.
There was also the cloning experiment involving Divine Tree Cells.
During the previous encounter, although Uchiha Ensei had been fleeing the entire time, it was not as though he had done nothing.
Before leaving, he used the Flying Thunder God's spatial transfer ability. After many attempts, he successfully cut a tiny piece off the Demonic Statue of the Outer Path.
The severed piece was only the size of a baby's fist, utterly inconspicuous compared to the Demonic Statue of the Outer Path.
But it was still part of the Divine Tree, so Uchiha Ensei intended to try cultivating it.
As for the result, he held no expectations.
After all, the Divine Tree could practically be considered the foundation of the Ōtsutsuki Clan.
With Uchiha Ensei's current technology, there was no possibility of producing any meaningful research results.
This was a long-term goal.
After completing these two preparations, the experiment to independently awaken the Mangekyō Sharingan was about to officially begin.
Unlike Itachi Uchiha, Uchiha Ensei had nothing important in his heart, no tragic experiences, nor the assistance of Kotoamatsukami.
Therefore, if he wanted a chance to awaken the Mangekyō Sharingan, he could only take another path.
For the choice of extreme emotion, Uchiha Ensei chose anger as the catalyst for awakening his Mangekyō Sharingan.
Next came a specially modified White Zetsu infused with Hashirama Cells.
White Zetsu cells were very similar to Hashirama Cells, yet the two were fundamentally different. Hashirama Cells possessed more vigorous Life Force, to the point of becoming extremely aggressive and easily going out of control.
White Zetsu, on the other hand, was a gentle existence, almost deathly still.
But if the Life Force of Hashirama Cells was injected into that gentleness, White Zetsu could unleash tremendous power.
As a biological weapon, White Zetsu was highly successful, but it required a powerful energy supply.
Uchiha Ensei had reason to suspect that Hashirama Senju's Wood Release might have originated from the Divine Tree, perhaps even personally engineered by Black Zetsu in order to cultivate Madara Uchiha's Rinnegan.
Of course, there was no evidence for such speculation.
But none of that mattered. What mattered was the White Zetsu suit Uchiha Ensei had created, infused with Hashirama Cells.
This thing could grant Uchiha Ensei regenerative abilities no weaker than Hashirama Senju's for a short time.
Uchiha Ensei clearly remembered that when the Sage of Six Paths awakened the Sharingan, it directly evolved into the Rinnegan, while his son Indra had directly awakened the Eternal Mangekyo.
Taking everything into account, as long as he possessed regenerative abilities similar to a Sage Body, the difficulty of awakening the Mangekyō Sharingan would surely decrease substantially.
Finally, Uchiha Ensei took out the tiny trace of special chakra he had extracted from Itachi Uchiha's brain and used the Transcription Seal Technique to seal it within each of his Sharingan.
"The success rate still doesn't seem very high..."
After pondering for a long time, Uchiha Ensei took out a Three-Tomoe Sharingan and performed a small operation on his palm. Then, he used the Transcription Seal on the Three-Tomoe Sharingan in his palm, sealing Izanagi within it.
Failure was one thing, but nothing could go wrong with his life.
With this safeguard, no matter what complications arose during the experiment, they could be remedied.
Immediately afterward, Uchiha Ensei injected the anger-inducing drug into his body without hesitation, followed by a drug meant to paralyze his flesh...
Under extreme anger, losing control was inevitable, so a method to restrain his body was necessary.
Then, during the last moments before the drugs took effect, Uchiha Ensei put on the White Zetsu suit infused with Hashirama Cells.
At once, Uchiha Ensei felt an immense surge of Life Force merge into his body.
Time passed second by second. The paralytic drug Uchiha Ensei had injected had already taken effect, and he had now lost control of his body.
Yet the effects of the anger-inducing drug had yet to appear.
Just as Uchiha Ensei thought his experiment had failed, an overwhelming fury rose in his heart from nowhere.
At the same time, the special chakra sealed within Uchiha Ensei's eyes began to merge into them...
But unfortunately, at that moment, Uchiha Ensei's mind contained nothing but rage.
If he had not already lost control of his body, the trump cards he had treasured for so long would likely have been unleashed one after another.
Three months later, a pale-faced Uchiha Ensei emerged from the laboratory, his eyes still carrying a complex mix of joy and conflict.
"Ensei? Did your experiment succeed?"
Chachamaru, who had been waiting outside the door for three months, asked with a face full of concern.
But Uchiha Ensei knew that Chachamaru did not truly care about his safety. He merely wanted Uchiha Ensei to help him conduct Sage Chakra research experiments on a few more female cats from the Ninja Cat Clan.
Uchiha Ensei had no particular thoughts about such matters, but Cat Granny knew that Uchiha Ensei's research into Natural Energy was still insufficient.
Thus, in the entire Ninja Cat Clan, only Chachamaru had continued to possess the ability to wield Sage Chakra.
"No, the experiment to awaken the Mangekyō Sharingan failed. But I accidentally discovered something even better..."
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