Spirit Light Jade

Two years passed in the blink of an eye. Jiraiya's rigorous training had helped the boys make tremendous progress.

Yuehua Ai was now a little over eight years old. His appearance and personality had hardly changed; he was still a quiet, handsome child with a slightly feminine air.

His slender figure was reflected in the gently flowing river. Yuehua Ai stood motionless on the bank, gazing absently at the ripples that occasionally appeared on the water.

Time really flew. He felt a little wistful. With a certain day drawing near, he had privately spoken with Jiraiya a few days earlier and gotten his approval for a request.

After the bandit incident, Jiraiya had begun a new stage of training for them. That stage focused on studying ninjutsu in greater depth, and they had spent two years at it.

This new stage of learning had set the boys on their paths as ninja. Jiraiya believed in tailoring his teaching to each student, so naturally he tested everyone's chakra affinities in order to devise a suitable training plan for each of them. Though he didn't have Chakra Paper to test them quickly and directly, he was still able to determine their affinities by observing how well they took to different techniques as they learned ninjutsu.

Yahiko had a Water affinity, while Nagato had an affinity for all chakra natures. Konan's chakra showed no particularly strong affinity among the five elemental natures, but Jiraiya had determined that she was especially suited to training in Yin Release techniques.

Yuehua Ai's chakra showed both Water and Wind affinities. Water was the most common nature in the Land of Rivers, while Wind was comparatively rare. But even though Ai had both Wind and Water affinities, his talent for chakra was nowhere near Nagato's. To this day, he still remembered the astonished disbelief on Jiraiya's face when he sensed Nagato's talent.

Of course, Nagato's talent had been well within Yuehua Ai's expectations. He was a little envious, but otherwise didn't think much of it.

Jiraiya excelled at Earth and Fire Release techniques and had also achieved great mastery of Yang Release. Though his affinities didn't match the boys', that didn't affect the quality of his teaching. As one of the Sannin, he was already among the handful of people near the pinnacle of the Ninja World. Although he hadn't trained in Wind Release, Water Release, Lightning Release, and the like, his insight into ninjutsu still let him teach from a position of great expertise. Moreover, his approach wasn't the kind of rote, mechanical instruction that spoon-fed students. He focused more on the boys' individual development and initiative.

Jiraiya's lessons mostly consisted of sharing the experience he had gained from training in ninjutsu and helping the boys work through the problems they encountered. As for the specific methods for learning each technique, he simply tossed them the scrolls containing the instructions and let them study on their own.

Yuehua Ai had now learned more than a dozen Wind Release and Water Release techniques combined. Though he hadn't trained in any particularly destructive techniques, he already felt that his strength far surpassed that of a Genin.

Yuehua Ai's approach to learning ninjutsu was different from everyone else's. While the others focused on practicing relentlessly, Ai was more interested in studying the principles behind each technique. During these years of training, he had recorded his insights and the patterns he had worked out on scrolls. His notes included detailed observations on how changes in chakra flow affected a technique, as well as the different effects produced by using different Hand Seals and chakra frequencies, volumes, speeds, and densities when releasing a technique.

The scrolls also contained ideas for variations on techniques he already knew, along with the initial designs for new techniques that had emerged from his accumulated experience.

He had organized these notes mostly because he was used to taking notes and keeping a diary in his previous life. To him, these records were nothing special, but in the eyes of anyone who truly understood the subject, they were no less important than a powerful secret or forbidden technique. The scrolls themselves were ordinary, but the words recorded on them cut straight to the heart of ninjutsu. They had long since surpassed the bounds of ordinary scrolls in value—an almost unimaginable value to the average ninja.

Because he understood the essence of ninjutsu, few people could match him in its application and variation. A D-rank technique might reach a strength of eighty or ninety in someone else's hands, but in his, it could reach a hundred and twenty. Among ninja of the same level, he was unquestionably at the very top.

If an ordinary ninja achieved what Yuehua Ai had, they would surely be more than satisfied. But after living two lives, Yuehua Ai had standards that ordinary, insignificant ninja could never understand.

All the boys were talented ninja. In Jiraiya's eyes, none of his new pupils was inferior to Namikaze Minato in talent, and the two who pleased him most were undoubtedly Nagato and Yuehua Ai.

Although Jiraiya had recognized him long ago, Yuehua Ai felt no pride at all. Nagato had been his goal from the very beginning, and no one understood Nagato's talent better than Yuehua Ai. Even though his own achievements had already earned everyone's attention, he knew they still couldn't compare with Nagato's talent.

Yuehua Ai had already surpassed ordinary people in his training in ninjutsu. What limited his strength now was his chakra. Though his spiritual talent surpassed Nagato's, that talent couldn't be converted into much strength.

Chakra was refined according to the bucket principle: it required a mixture of spiritual and physical energy. Yuehua Ai's spiritual energy had an extraordinarily high ceiling, but without any special constitution, he was firmly limited by his physical energy, the shorter stave in his bucket. No matter how strong his spiritual energy was, his physical energy would hold back his chakra refinement. So no matter how much chakra he refined, his reserves still depended on the state of his physical development.

Chakra was the foundation of all ninjutsu, and its advantages were far beyond those of any other form of power. Even if his spiritual strength was exceptional, using spiritual energy alone was too limiting. Spiritual energy left no trace when used for sensing and was more concealed than chakra, but it couldn't match the level of detail possible when sensing with chakra.

Chakra might seem to be nothing more than a combination of two kinds of energy, but together they encompassed nearly everything about a ninja: their nature affinities, physical traits, and spiritual characteristics.

Because his chakra was limited, Yuehua Ai shifted more of his energy elsewhere so he could grow stronger faster.

He devoted a great deal of time to swordsmanship and Shuriken techniques. And when Jiraiya sparred with them, he also learned the Rasengan—though he taught himself rather than receiving instruction from Jiraiya.

The Rasengan had many advantages and was one of the finest A-rank techniques. As a technique that required no Hand Seals, it was fast and easy to use, with inconceivable concealment and destructive power. Compared with Kakashi's proud original technique, Chidori, it was on an entirely different level in terms of practicality, even if it was less flashy.

Jiraiya wasn't the sort to hoard his knowledge. The main reason he hadn't taught the Rasengan to the others was his senior pupil, Namikaze Minato.

Minato had taught Jiraiya the Rasengan. It had taken Minato three years to develop it, and since he was still alive, Jiraiya had no right to teach his technique to others without permission—not even to his own junior students!

Yuehua Ai was very interested in the Rasengan. Since Jiraiya wasn't going to teach it to him, he could only learn by watching. After seeing Jiraiya use it a few times, Ai studied how his chakra changed as he performed the technique and combined his observations with what he knew about training in the Rasengan from his previous life. After countless experiments, he successfully recreated the technique, which required no Hand Seals. But he also discovered that a lot of what he had seen in the anime was completely unreliable.

It had taken Minato three years to develop the Rasengan. Given Minato's talent, the fact that it had taken him so long showed just how difficult it was.

Yuehua Ai had no idea how hard it was until he tried.

The core, crucial, and most important part of training in the Rasengan was chakra control. It was easy to imagine how difficult it was to gather countless streams of chakra, make them spin rapidly, and compress them into a highly stable sphere.

And that was only the chakra control involved. The forces at work, energy dissipation, and the principles of conversion and balance were no easier to handle. As for how Naruto would eventually learn the Rasengan, besides using Shadow Clones to share the workload, much of it came down to what he himself said: he couldn't remember it in his head, so he let his body learn it instead. The Rasengan Naruto released was the product of countless failures, until his body had learned it by instinct.

As soon as Yuehua Ai learned the Rasengan, he no longer needed to form the chakra with one hand and repeatedly press it with the other as Naruto had when he first learned it. He could release it faster and more easily. Even compared with Jiraiya, he was no less proficient.

Although he had learned the Rasengan, Yuehua Ai had never used it in front of Jiraiya, since Jiraiya hadn't taught it to him personally. He still planned to visit Konoha one day, and he didn't want his ability to use the Rasengan to drive a wedge between Minato and Jiraiya. Jiraiya wouldn't mind and would explain that Ai had taught himself, but would Minato really believe it? Would he truly not mind? It was like spending countless hours and tremendous effort to finally achieve something, only to have someone else quietly make use of it. Who wouldn't feel resentful in that situation?

Yuehua Ai wasn't naïve; he considered many things. He didn't think of the Rasengan as his own, so unless absolutely necessary, he generally avoided using it. He had also asked Yahiko and the others to keep it a secret that he had learned the Rasengan.

The Rasengan was still an incomplete technique. It didn't incorporate changes in chakra nature, and it also had a major flaw: it couldn't be thrown.

Beyond its destructive power, the Rasengan served another, more important purpose for Yuehua Ai: it helped him practice chakra control. The Rasengan was a technique that took shape transformation to its extreme, and its precise control had benefited Ai immensely.

As he continued to study ninjutsu in greater depth and spent more time secretly practicing chakra control with the Rasengan, Yuehua Ai began to consider what more he could do with it.

He wanted to solve the Rasengan's flaw and create a powerful offensive technique of his own!

Once he had a goal, Yuehua Ai couldn't hold back. After more than a month, he finally modified the Rasengan using knowledge from his previous life and made it truly his own. He named the technique Spirit Light Jade!

Spirit Light Jade still used the Rasengan's principle of rapidly spinning and compressing chakra, but it also incorporated many concepts from the physics he had studied in his previous life.

When it came to rotation, two examples stood out most in Yuehua Ai's mind: planets orbiting stars on the cosmic scale, and electrons orbiting atomic nuclei on the microscopic scale.

Drawing on the atomic model, Coulomb's law, the Pauli exclusion principle, and various other ideas from physics and energy theory, Yuehua Ai established a central principle and three foundational principles for his new technique.

He used three main Chakra Threads as its framework, making them occupy three-dimensional space and converge toward the core like a whirlpool. The three paths and one core formed a system in which each path was both a relatively independent small chakra loop and part of the new technique's larger loop. By increasing the amount of chakra flowing through the three paths, the chakra at the core would keep gathering and collapsing inward.

Inside the space formed by the technique, the three main chakra paths took the most stable shape possible: a triangular pyramid. The chakra along each path could move in a circular orbit and loop in harmony with the whole.

At first, Spirit Light Jade appeared as three wispy streams of chakra gathering together. As the user poured in more chakra, it became increasingly compressed and stable. Once the chakra reached its full state, it could circulate on its own, taking on the perfect spherical shape of the Rasengan. Aside from the Rasengan being blue and Spirit Light Jade being jade-white, the biggest difference was the faint, shifting glow around Spirit Light Jade, like the spiral arms of a galaxy!

Unlike the Rasengan, Spirit Light Jade solved the problem of the chakra sphere being unable to leave the user's hand. Spirit Light Jade was a large chakra loop formed from three small chakra loops synchronized at the same frequency, and the chakra collapsing inward at its core served to draw it in and stabilize it.

If the user released one of the three chakra frameworks as a source of propulsion without disrupting the core's operation, Spirit Light Jade could be launched at supersonic speed.

Once launched, Spirit Light Jade would no longer be in its most stable state. Though two chakra frameworks remained, they could no longer maintain absolute balance as before. So as soon as it encountered an external force, the remaining two main chakra paths would collide and annihilate each other, completely shattering the balance inside the chakra sphere. This would cause the high-density chakra energy collapsing at the core to erupt, releasing all its energy in an instant.

When its overall balance was maintained, Spirit Light Jade could compress more chakra than the original Rasengan, making it considerably more powerful. But it demanded far greater chakra control and a much deeper understanding of balance. Without understanding planetary motion and the atomic model, it was virtually impossible for any other ninja to recreate Spirit Light Jade.