The moment Bai Sui condensed this pearl of qi, he felt some changes taking place within him.
First, the qi between heaven and earth had become more responsive. It seemed to want to rush into Bai Sui's dantian at every moment, but his reservations had kept him from letting it.
Second, Bai Sui could use the power of his Primordial Spirit to a certain extent. For instance, he could sense whether people around him meant him well or ill, and get a general sense of their energy. In that respect, it was similar to the Mind's Eye of the Kagura.
It was only similar, however, because there was more to it than that. When Bai Sui meditated each day, his Inner Landscape sometimes offered glimpses of the future. For example, during one session the day before, he had suddenly seen an unfamiliar face. The next day, that person had come looking for him.
Bai Sui's mind had also become exceptionally steady and focused. Though he hadn't put it to the test, he felt that ordinary genjutsu probably couldn't affect him anymore.
He had also grown more attuned to plants and animals. He still couldn't communicate with them directly, but he was already far more attuned to them than an ordinary person.
His body had changed considerably, too. Rather than bulking up with knotted muscles, he had become supple and strong. His senses had sharpened, his appetite had increased dramatically, and his digestion had improved by leaps and bounds. He was one step closer to no longer needing to relieve himself.
Now that he could sense energy, Bai Sui naturally tried it out in private.
By his estimation, the energy within him was already on par with that of the Uzumaki Clan member in charge of this area.
The Uzumaki Clan was renowned in the Ninja World for its chakra and Sealing Jutsu. Bai Sui didn't know whether that person was a jonin, chunin, or genin, but he figured his energy reserves were already pretty substantial.
Of course, that didn't mean Bai Sui could protect himself yet. He didn't have any techniques for using qi.
It was like having bullets but no gun. If he really had to fight someone, he might be able to use the bullets like a hammer against an ordinary person.
But against a ninja, it would be like taking on someone with a machine gun while wielding a flail. What's more, his opponent might belong to a prestigious clan with deep roots, like the Uzumaki.
So Bai Sui's top priority now was to find ways to use energy. First of all, his qi really was different from chakra, even though both were made up of physical and spiritual energy.
Chakra was produced by combining spiritual and physical energy in roughly equal parts. It was formed as needed and generally wasn't stored. To Bai Sui, it felt like twisting a copper wire together with a tin one.
Bai Sui's qi, on the other hand, was made by refining physical energy with spiritual energy, then using the physical energy to condense the spiritual energy, until the two fused. It was like combining molten copper and tin to make an alloy.
Both had their advantages. Chakra's nature made it quick to refine. After resting for about half a day, one could generally replenish one's chakra.
As for qi, at least for Bai Sui at present, it was extremely difficult to refine. Every use diminished what he had, and though he refined it constantly, it would take him at least several days to fill his reserves.
Of course, a person's chakra reserves were basically fixed. Once someone reached adulthood, they generally stopped growing. In other words, a person's potential was set from birth.
Qi, however, had a whole series of cultivation methods ahead of it. One could expand one's reserves and refine it further. As long as one was still alive, it would grow stronger with every passing moment. It was the path of a late-game player.
As for controlling it, Bai Sui had secretly watched for the past few years and had luckily seen ninjutsu performed a few times. It seemed that Natural Energy might be involved.
After analyzing it in secret—or, more accurately, speculating—Bai Sui figured that ninjutsu could take on different properties because the fifty percent of chakra made up of spiritual energy drew on the Natural Energy between heaven and earth, while the other fifty percent, the physical energy, controlled it.
Thanks to his memories of his previous life, Bai Sui knew that Naruto had explained several ninjutsu techniques in detail. But no matter how he experimented, he found that he couldn't use his qi to perform ninjutsu directly.
Bai Sui was sure there were reasons he didn't understand, but he didn't think he was capable of figuring them out. After all, this was a difference between two worlds. He wasn't some peerless genius who could easily bridge the gap between their systems—or even between the two worlds themselves.
So all Bai Sui could do now was develop ways to use qi. Had there been records of such methods in his previous life? Of course. But he'd only ever been interested in ghost immortals, so he'd never collected or studied material on this subject.
Now all Bai Sui could do was experiment based on some of the theories from his previous life. Fortunately, he did know a little about the subject.
The Yellow Emperor's Inner Canon: Basic Questions described five ways qi could move: absorption, release, accumulation, transmission, and storage.
Absorbing qi corresponded to growth and the Wood phase, whose function was to spread and unfold; releasing qi corresponded to dispersal and the Fire phase, whose function was to blaze upward; accumulating qi corresponded to coagulation and the Metal phase, whose function was to transform; transmitting qi corresponded to cooling and the Water phase, whose function was to flow downward; storing qi corresponded to nourishment and the Earth phase, whose function was to nurture and produce.
The five phases—Wood, Fire, Earth, Metal, and Water—corresponded to the five organs: liver, heart, spleen, lungs, and kidneys. After trying them one by one and drawing on what he knew from his previous life, Bai Sui eventually managed to develop a Qi Sword.
He nurtured a breath of qi in his lungs, and as time passed, its power grew stronger and stronger.
His tests showed that if he skipped the nurturing entirely and simply inhaled and spat it out, its power was like a one-year-old child's punch. It could still injure someone if it hit a vulnerable spot like the eye.
If he nurtured it for a month, it could pierce several feet into stone. It could probably punch straight through Earth Release: Earth-Style Wall. Its power was quite impressive. The problem was that it could only be used once. He couldn't use it again until he had nurtured another breath.
Through his experiments, Bai Sui had also found that with his current abilities, he could store a maximum of three breaths of qi at once. That meant he could release the Qi Sword up to three times. Its power depended on how long he nurtured each breath.
Bai Sui also remembered that in his previous life, knights had been divided into nine ranks. If he mastered the Qi Sword, he could probably make himself a Qi Knight.
Law said: "There are nine ranks of immortal knights, each distinct from the others. First, the Heaven Knight; second, the Immortal Knight; third, the Spirit Knight; fourth, the Wind Knight; fifth, the Water Knight; sixth, the Fire Knight; seventh, the Qi Knight; eighth, the Ghost Knight; and ninth, the Sword-Encountering Knight."
First, the Heaven Knight: a celestial immortal bestowed with a sword by God.
Second, the Immortal Knight: one who has cultivated the path of ascending to the heavens as a perfected immortal, and has also refined qi into a cone-shaped sword.
Third, the Spirit Knight: an Earth Immortal who dwells atop a mountain and has forged a dagger. If word reaches him from ten thousand miles away of injustice, his flying sword will arrive at once. Thus he is called a Spirit Knight.
Fourth, the Wind Knight: also an Earth Immortal, who has forged a dagger but whose cultivation is intermittent and has not reached the utmost spiritual heights. When he learns of injustice, he rides the wind, and he and his sword arrive together.
Fifth, the Water Knight: originally a water immortal who has completed his cultivation. He is called a Water Knight. He can soar through any place where there is water.
Sixth, the Fire Knight: one who begins his cultivation by immolating himself. He is also known as one who has mastered the Samadhi Fire. After forging a dagger, when he is ready to soar, he must transform into a ball of fire and ride it wherever he goes. Thus he is called a Fire Knight.
Seventh, the Qi Knight: one who studies breath control and refines his essence into a sword. Once forged, the sword is like qi, and he travels by wielding it. Thus it is called a Qi Sword.
Eighth, the Ghost Knight: one whose form cannot be seen. He originally cultivated the immortal art of ink-wash forms, creating an ink-wash sword. He comes and goes just like qi.
Ninth, the Sword-Encountering Knight: one who happens upon a treasured sword and gains the ability to manifest it at will, wherever he goes.