Sasuke understood the argument presented in the book. After all, Fire Release ninjutsu itself was a method of release that injected "nothing" nature chakra into "fire" nature chakra. Learning enough Fire Release ninjutsu and using it frequently until he became proficient was itself a process of strengthening and mastering nature transformation.
Some advanced Fire Release ninjutsu involved not only nature transformation but shape transformation as well. Dragon Flame Jutsu, Dragon Flame Song Dance, and Phoenix Flame Dance all altered or compressed Fire Release ninjutsu that was originally nothing more than a ball of fire, turning it into lifelike dragons or phoenixes to focus or expand the technique's power and attack range.
Were the methods recorded in the book really the only ones?
If he directly trained nature transformation like Naruto, progress would be very slow under his current circumstances.
But following the book's methods was not a good idea for him right now, either.
At present, he could only practice releasing two or three Fire Release techniques a day. After all, if he wanted to improve his strength as quickly as possible, he had to reserve most of his chakra for Shadow Clones to study with.
Hmm...
The defining trait of Fire Release was temperature—or, more precisely, high temperature.
Since the knowledge of this world could not solve Sasuke's current problem for the time being, he turned his thoughts to what he had learned in his previous life.
From a physics perspective, temperature was a manifestation of how intense the thermal motion of an object's molecules was.
The faster molecules moved, the higher the temperature and the hotter the object; the slower they moved, the lower the temperature and the colder the object.
Put simply, friction generated heat!
At that thought, Sasuke wore an enlightened expression, as if he had suddenly understood something.
"If I'm right, then..."
No sooner had he thought of it than he acted. Sasuke gathered another ball of chakra in his palm. He did not yet understand the true nature of chakra, much less whether chakra contained molecules, atoms, or anything of the sort.
But that did not stop him from imitating the theory of molecular thermal motion and doing something similar.
There was still a ball of chakra in his hand, but within that chakra, countless tiny strands of chakra were remotely controlled by him, continuously colliding and moving at a relatively slow pace, mimicking the frictional movement between molecules.
The moment he held his hand near it, visible mist began to rise from the kettle in a short time, and the water inside started boiling again.
"Ha ha ha ha! Just as I thought!"
"The ancients truly did not deceive me. Science is power!"
Sasuke could not help but feel delighted at the sight.
But that happiness lasted only a few breaths. Sasuke quickly calmed down and continued thinking.
First, under normal atmospheric pressure, water boiled at one hundred degrees Celsius. That temperature was barely adequate even against ordinary people, and it was nowhere near enough against ninja. Defeating an enemy with nothing but fire-nature chakra in his hand was basically impossible.
He could make up for that in the future by increasing the speed of the tiny chakra particles within his chakra. Perhaps one day, he could achieve something on the level of Wind Style: Rasenshuriken.
However, that also involved training his chakra control.
Second, this was an advantage. In the future, he could imitate molecular thermal motion and incorporate the principle of intermolecular movement when releasing fire-nature chakra from his mouth, allowing Fire Release ninjutsu such as the Great Fireball Technique to be hotter and faster when launched from his mouth!
However, he also had to pay attention to the degree of it, lest the chakra in his mouth moved too fast and became unstable, burning his mouth.
He had solved one problem only for two more to arise, but Sasuke did not mind in the slightest.
The wiser someone was, the more problems they discovered. They would better understand their own shortcomings and become more humble.
Only a frog at the bottom of a well would think that the patch of sky above the well was the entire sky.
Sasuke quietly closed his eyes. As long as he could identify the problems and confirm that the path was correct, then nothing was truly a problem.
As was his habit, he summarized what he had gained that day on paper. After reviewing it once in his mind, he promptly destroyed it.
It was already late at night. Sasuke had finished his day of training and returned to his room, but he did not rest immediately. Instead, he lay prone on a mat atop the tatami, bent his elbows, planted his palms beside his waist, straightened his legs, and pressed the tops of his feet against the floor. He inhaled, straightened his elbows, and lifted his body off the ground, supporting himself with his palms while keeping the tops of his feet pressed down. As he exhaled, he raised his head and looked toward the ceiling.
At the same time, he exhaled whenever he bent his body forward and inhaled as deeply as possible when contracting his body. It looked like a very strange movement.
Yoga!
The movements Sasuke was doing naturally came from the yoga of his previous life.
In his previous life, he had been a fitness enthusiast. Like most men, he had chosen to lift weights, while his girlfriend had chosen yoga.
He had never practiced any yoga in his previous life, but through their long cohabitation and constant exposure to it,
he was no stranger to yoga as a form of exercise, and he had memorized the key points and proper forms of those movements.
Two months ago, after deciding on his training plan, he had begun seriously studying yoga. Every night before sleeping, he spent an hour practicing it.
Yoga was a fitness exercise that could train the body's flexibility while promoting blood circulation and expelling toxins. Practicing yoga could also provide an effect similar to a massage. For someone like him, whose daily regimen was nearly demonic training, it was an excellent way to relax.
Beyond its physical benefits, yoga could also soothe the mind and spirit, achieving the effects of focusing the mind, calming the spirit, entering meditation, and quiet contemplation.
The meditation training Sasuke had previously planned as a means of increasing spiritual energy referred to yoga and the Yoga Meditation Technique.
In ancient times, yoga had been one branch of the six major schools of philosophy. Its cultivation was divided into seven stages: Muladhara, Svadhishthana, Manipura, Anahata, Vishuddha, Ajna, and Sahasrara. Reaching the highest stage meant attaining Brahman-Atman Unity.
Legend had it that before Shakyamuni became a Buddha, he had been a master of yoga asceticism. Later, Buddhist meditation also incorporated much from yoga meditation.
Naturally, the yoga Sasuke studied was not the yoga of ancient religions, but simply a form of exercise for physical fitness and mental well-being found in yoga studios everywhere in modern cities.
The concept of chakra in Hokage came from yoga's energy centers, referring to the energy centers distributed throughout the human body—especially those arranged along the body's central axis from the tailbone to the crown of the head. These were the Three Channels and Seven Chakras!
He did not know whether the yoga of his previous life and the chakra of this world had some special connection, but after two months of training, Sasuke could clearly feel that his spirits had improved and that the speed at which he refined and circulated chakra had also increased.
Since it could increase his strength while relaxing both body and mind, it killed two birds with one stone.
So Sasuke continued to persist with it.
Before you continue