As Shazo's Wood Release grew increasingly refined, the difficulty of training also increased.
It was not that performing ninjutsu was difficult, but clearing away the traces took far too much time.
The forests Shazo created with Wood Release were growing larger and larger. Even clearing away only the most outrageous giant trees took dozens of times more time.
After an entire night, he could barely practice a few times.
As the forests he created expanded, the trees' canopies grew taller and their trunks thicker, and the time needed for cleanup continued to rise.
Shazo could not help but worry. At this rate, he would soon be unable to train in the village.
Once he resolved the Uchiha clan massacre and saved Uchiha Izumi's family, he would steadily take the exams and advance to Chunin.
Then he would accept C-rank Missions, leave Konoha, and freely train his Wood Release outside.
Suddenly, Shazo knocked himself on the head.
Why was he being so narrow-minded?
Wood Release was the Kekkei Genkai he had naturally awakened, but the reason he had kept training it was because it held unparalleled deterrent power in Konoha. Its ability to prevent the Uchiha massacre was irreplaceable.
Even Dust Release, a Kekkei Tōta, was far inferior.
But the fact that Wood Release affected such a vast area during training proved that Shazo had already achieved his goal. There was no need to keep making things difficult for himself by training it.
Rather than spend so much time clearing away the traces of Wood Release, he might as well continue studying the later sections of Five Spirits Battle True Interpretation and fuse a second Kekkei Genkai.
That would be the most efficient approach.
Having made up his mind, Shazo began recalling the contents of Five Spirits Battle True Interpretation and considering which second Kekkei Genkai to choose.
He first ruled out Kekkei Genkai that caused too much commotion, such as Explosion Style and Boil Style.
Next, he ruled out those lacking in power, such as Scorch Release and Lava Style.
In the end, Shazo wavered between Magnet Style and Swift Style.
In his previous life, Shazo had been a science student, and he had also been a diehard anime nerd who believed in electricity dancing at one's fingertips. How could he not understand the potential represented by Magnet Style?
Magnetism was one of the four fundamental forces. It could be unified with the weak force and had the greatest hope of achieving a grand unification of all four fundamental forces.
Its potential was not merely immense—magnetism also had incredible style.
Bilibili's Electromagnetic Cannon, Magneto, master of the scene, and the great figures of Sea Tiger's Magnetic Field Rotation all proved that magnetism was the most prestigious power.
Master it, and it would be genuinely cool.
But Swift Style was also excellent.
Although there were not many figures known for extreme speed, they all seemed so relatable to Shazo.
There was the ultimate killing king who believed that all martial arts under heaven could be broken by speed alone, and The Flash, a tool who could restart the timeline whenever he wanted.
The Ninja World itself also had the Yellow Flash Minato Namikaze, the Body Flicker Shisui he had just met, and A, the Fourth Raikage of Kumogakure. All of them were famous top-tier Kage-level Ninjas.
After struggling for five minutes, Shazo chose Swift Style.
There was no other reason. It was the most covert Kekkei Genkai.
As long as he did not stupidly introduce himself, and used harmless chakra fluctuations as suitable cover, even if he used Swift Style right in front of the Third Hokage, Hiruzen Sarutobi would not be able to tell.
Shazo found the section on Swift Style in Five Spirits Battle True Interpretation and muttered aloud to reinforce his memory and deepen his understanding.
"Mm, Swift Style is formed by the qualitative fusion of Wind Style and Lightning Release. The direction of Wind Style's qualitative change is flow."
"Mm, I understand. It moves the air from the front of motion to the rear, creating a vacuum and low pressure ahead, while producing high-pressure propulsion behind."
Shazo found it rather strange. Wind Style's qualitative change was a perfectly normal direction. Who knew how many Wind Style ninja had tried it before? Why was Swift Style still so rare?
But he immediately understood why. "The direction of Lightning Release's qualitative change is... weak electricity?"
"Oh, I get it. Judging from these specific figures, the direction of Lightning Release's qualitative change is bioelectricity in the nerves."
"Hahahaha! No wonder ninja can't create Swift Style. It's another direction of qualitative change that goes against the Ninja World's obsession with combat power."
"The core internal organ for fusing Swift Style is..."
Suddenly, Shazo's eyes widened, and even his fingers began to tremble.
"Why the kidneys? How could it be the kidneys?"
"Wind Style and Lightning Release churn and fuse around the kidneys... Th-this will kill someone."
Among the human body's internal organs, the liver had the strongest regenerative ability and was not very sensitive to pain, which was why liver cancer was often discovered only in its late stages.
But when he had fused Water Release and Earth Release before, even though they were the two gentlest types of chakra with the mildest qualitative properties, the pain had still left Shazo drenched in cold sweat.
The kidneys, however, were organs extremely sensitive to pain. Even a tiny kidney stone could leave a grown man unable to stand.
Shazo had suffered from kidney stones in his previous life. During those few hours of an attack, the pain he felt had been catastrophic.
That night, Shazo had clung to an emergency doctor and wailed his eyes out, snot and tears smeared all over his face. He had only come back to life after enduring until dawn and undergoing ultrasonic lithotripsy.
Shazo's dignity had suffered a devastating blow, and from then on, he had lived without shame.
What was even worse was that the kidneys were among the human body's most fragile organs. Their poor regenerative ability meant they needed to be specifically duplicated to deal with the high likelihood of kidney necrosis.
If the fusion process caused irreversible damage, Shazo would have to face frequent urination, urgent urination, incomplete urination, and even ED at the tender age of fourteen...
Life probably would not be worth living anymore.
However, at the end of the Swift Style section in Five Spirits Battle True Interpretation, there was an additional note left by Demon Xiazhuo.
The moment Shazo saw it, his despondency vanished. He sprang to his feet and shouted excitedly, "Let's do this! Rise up!"
"Swift Style—I'm definitely going to fuse it!"
What could make someone ignore certain pain and danger and still press forward?
The first thing that came to mind was hatred!
For example, if a middle-aged father lost his only child, he could disregard death in pursuit of revenge.
Beyond hatred, sufficiently great benefits and desires could also make people disregard danger and risk.
For instance, upon seeing an opportunity for three hundred percent profit, capitalists could ignore the risk of death.
For instance, when Shazo saw the discussion of methods for treating kidney damage at the end of the Swift Style fusion chapter of the Kekkei Genkai section—especially the four words Demon Xiazhuo had added: "Emperor Engine."
Shazo immediately felt certain that he could ignore the kidney pain that had once made him wish he were dead.
During the process of fusing Swift Style, Wind Style and Lightning Release would inevitably damage the kidneys and cause terrifying pain, but it was also a process of strengthening them.
Five Spirits Battle True Interpretation made it very clear: Swift Style did not merely require chakra to break through the wind and accelerate reflexes. It also required powerful kidneys.
Strong kidneys could provide sufficient adrenaline. Adrenaline could strengthen the reflex speed of nerves and muscles, reduce pain, and prevent the body from being torn apart by the speed forcibly raised by Swift Style chakra.
Powerful kidneys could also withstand the consequences of surging adrenaline and rapidly expel toxic adrenaline metabolites.
In short, Swift Style required the support of a pair of Emperor Engines in order to run wildly as free as the wind.
Without strong kidneys to support it, even if one awakened Swift Style, they would only be a defective product who collapsed panting after three steps.