Over the past month, Neji had not abandoned his observation of the animals in the laboratory outside the village. He had indeed discovered some abnormalities: animals injected with Natural Energy Diluent generally showed signs of cellular fibrosis at and around the injection site.
Moreover, some animals injected with higher concentrations had already lost sensation in the injected area, their skin completely necrotic. While it was not life-threatening, the effects were considerable. Most likely, excessive Natural Energy contact in localized areas had caused the cells to operate and divide under high loads for too long, ultimately leading to premature necrosis.
Increasing the Natural Energy in the air, on the other hand, was a gradual process that improved every bodily function across the board. It would not cause the drawbacks brought about by uneven enhancement of different body parts.
This made Neji grateful that he had not been tempted by quick results and chosen to absorb Natural Energy through injections, which worked fast and effectively. Next time, he would play it safe and keep the concentration below four hundred.
At this stage, improving his own strength remained his top priority. Whether it was "Nest-Building," "Gene Completion," "Shennong Encyclopedia," "All Tailed Beasts Collected," or "Kekkei Mōra," they all existed to serve that goal.
At present, the best way to increase his strength was undoubtedly to use Natural Energy to transform his body into a Sage Body. The difficulty of this transformation also depended on age: the older one was, the harder it became. Even if an elderly person were forcibly transformed into a Sage Body, they would lose any room for further growth and remain forever at the initial stage.
Thus, Neji abandoned all unnecessary plans and devoted himself entirely to sensing and attempting to absorb Natural Energy.
Neji told Sasuke and Haku that he would be entering seclusion for a long time and asked them not to worry. Then he immersed himself wholeheartedly in cultivation.
Neji spent nearly two months keeping himself completely submerged in an environment saturated with high concentrations of Natural Energy, suppressing his urge to absorb it.
Only after he felt that his body had completed its initial adaptation to Natural Energy did he guide a minute amount of it into his body. He circulated it through several relatively safe and stable acupoints and the meridians connecting them, then, after forming a preliminary Internal Circulation, stored that Natural Energy in his Dantian.
He slowly increased the amount of Natural Energy he absorbed in this gradual manner, continuously circulating it through the Internal Circulation he had established. It tempered the meridians and acupoints within that circulation, as well as his major bodily tissues and bones.
Repeating this cycle over and over, Neji became completely immersed in the joy of cultivation and improvement. He felt the Natural Energy within him steadily grow stronger, his physical condition improve, and his overall Chakra increase.
More than a year later, Neji hit a bottleneck. The Internal Circulation he had formed could no longer further improve his various physical attributes, so he stopped cultivating.
Neji guessed that this was most likely because the Internal Circulation he had initially established involved too few acupoints and meridians. It could not account for the growth of his entire body, and after strengthening the areas around the circulation he had established, he no longer had the ability to reinforce the remaining regions.
It was like a good internal cultivation manual, which could train an enormous number of acupoints and meridians at once and cover nearly every part of the body. A commonplace internal cultivation technique, however, could only account for certain areas and could not train the entire body.
The preliminary Internal Circulation Neji had created himself was probably a very poor cultivation method, capable at most of raising his body to the level of an Initial Sage Body.
To improve further, he could only expand the acupoints and meridians covered by his Internal Circulation, striving to strengthen his entire body without overlooking any area.
Yet that process was exceedingly dangerous. Some vital acupoints could inflict tremendous harm on the body with even the slightest contact.
That was why Neji had not blindly probed around. Once he had fully adapted to his current state, he would slowly and gradually try to expand the coverage of his Internal Circulation.
Until he had completely achieved the Perfect Sage Body. Even though he had only attained an Initial Sage Body for now, its rate of growth was astonishing. Over the past year and a half, he had not deliberately refined Chakra, yet the Chakra reserves within his body had reached 5,400 Ka, meeting the Kage-level standard.
His Chakra recovery speed was twenty times what it had once been, while his injury recovery speed was more than ten times faster. Every one of his physical metrics had improved significantly.
The greatest change was that, aside from Chakra, his body now stored a certain amount of Natural Energy. When he used ninjutsu, mixing in a certain amount of Natural Energy could multiply its power.
Or rather, ninjutsu infused with Natural Energy could no longer be called ninjutsu. It was called: "Sage Jutsu"!
Whether it was Jiraiya, Hashirama Senju, or Naruto, they all needed to gather Natural Energy on the battlefield before using Sage Jutsu. Depending on their affinity with Natural Energy, this process could take more or less time, making it extremely inconvenient to use.
Through his Internal Circulation, Neji constantly stored a certain amount of Natural Energy in his Dantian. This meant that, before the Natural Energy in his body ran out, Neji did not need to absorb it from the outside world on the spot and could launch Sage Jutsu attacks or defenses anytime, anywhere.
The difference between the two was obvious!
What delighted Neji even more was that using the mixed energy of Natural Energy and Chakra within his body—hereafter called Sage Chakra—to cover the Caged Bird Seal could block and isolate the Caged Bird, allowing him to break free of its restraints to a certain extent.
Though he had not completely broken the Caged Bird, from this day onward, he was truly free. No person and no matter would ever restrain him again.
He could finally let loose and do the things he wanted to do.
After more than seven years in the world of Naruto, Neji finally felt truly relaxed and free. Only now did he feel as though he was truly alive.
At twelve years old, he had grown to one meter seventy-five!
The reason he chose to emerge from seclusion now was, on one hand, that his cultivation had reached a bottleneck and he could only grow stronger by expanding his Natural Energy Internal Circulation. On the other hand, he was about to graduate, lose the cover provided by the Ninja Academy, and become an official Genin.
Over the past year and a half, Neji had not been the only one in the cultivation chamber. He had also brought along the two Thunder Rocs he had taken back for experiments last time and cultivated with them.
The two Thunder Rocs had also developed a trace of Natural Energy within their bodies. They could synthesize Sage Chakra and use Sage Jutsu. It was an unintended outcome, but he had raised two rather formidable flying mounts for himself.
However, because they grew too quickly, the two Thunder Rocs had only accompanied him for a little over half a year before being released back into the Summoning Realm, as the cultivation chamber could no longer contain them. Otherwise, they could have grown even further. It was somewhat regrettable.
As the saying went, after long stillness came the urge to move. Neji planned to go out and stretch his limbs, adapting to his rapidly increased strength!
When Neji walked out of the laboratory, Haku and Sasuke were no longer surprised. Ever since Neji had built the underground laboratory, every time he emerged, he underwent visible changes—not only in strength, but also in temperament, height, presence, and more.
Once, Sasuke had been so curious that when Neji went out to replenish the Natural Energy Compression Fluid, he encouraged Haku to explore the underground cultivation chamber with him.
Haku was somewhat curious as well, though not as strongly as Sasuke. Besides, Neji had never forbidden them from going to the underground cultivation chamber. It was just that whenever Neji cultivated, the chamber was closed off behind three doors, which had dispelled Haku's desire to explore.
Now that Neji was absent and the laboratory apparently had not been locked, Haku followed Sasuke down to take a look out of curiosity.
The result, however, was disappointing. Aside from the three doors being rather strange, there was nothing special inside the cultivation chamber. The walls were simply thicker, and the sealing was better.
Having failed to find the answer he wanted in the laboratory, Sasuke had also asked Neji directly. But whenever the subject came up, Neji would only smile without saying a word. His expression perfectly conveyed: I have secrets, and I'm not telling you!
It infuriated Sasuke to death, yet there was nothing he could do!
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