"In other words, when a Shadow Clone dies, the memories it experienced are transmitted back to the main body. So, besides memories of death, there are also memories of training."
Uchiha Nagi said, "Therefore, if you train with ten Shadow Clones, your speed will also be ten times faster. Understand?"
Muichiro's eyes widened, his face filled with disbelief. "I see! No wonder Mr. Uchiha is so strong. Are you training at ten times the speed every day? You truly are a genius!"
"Ahem..." Uchiha Nagi felt a bit embarrassed by his words. "Training other things is fine, but Breathing Techniques... I tried, and it doesn't seem to work."
Uchiha Nagi sighed helplessly and explained the nature of the Shadow Clone to Muichiro. Essentially, it's formed from Chakra and lacks internal organs, making it difficult for a Shadow Clone to simulate breathing to control all muscles and blood in the body, which is what Breathing Techniques require. However, it's excellent for practicing other things, such as Ninjutsu—
So, after Uchiha Nagi's explanation, Muichiro left with a grateful expression, confident that he would become even stronger by accelerating his Ninjutsu training.
In the following days, Uchiha Nagi began to summarize the Breathing Techniques he had learned during this period, the most proficient of which was Water Breathing.
Then, Flame Breathing also became proficient under the Flame Pillar's guidance a few days prior, and with the copy and replication from the fight against Akaza that night, it could barely be considered proficient.
What amazed Uchiha Nagi the most was Thunder Breathing First Form, inspired by Zenitsu.
In the later stages, Zenitsu was able to develop skills like Thunderclap and Flash Sixfold, Thunderclap and Flash Eightfold, and Thunderclap and Flash Godspeed based on the single-form Thunderclap and Flash, showing Uchiha Nagi a different path.
Because the First Form of Thunder Breathing is just about speed, but Zenitsu directly developed a composite form that can flash multiple times at once. And Uchiha Nagi possesses the Mangekyo, so his dynamic vision is perfectly fine, and he can also become a Golden Flash—
Uchiha Nagi activated the Breathing Technique of Thunder Breathing, took a deep breath, and then in the next second, activated his Three Tomoe dynamic vision.
"Thunder Breathing, Thunderclap and Flash Eightfold—"
In an instant, after a golden lightning flash passed through the eight dummies in the courtyard, a cut appeared on each of their necks. The entire process took less than a second.
"It's still not enough. These eight dummies are all clustered together. What if the enemies are spread out?" Uchiha Nagi muttered to himself.
Ninja do not all gather together during combat, because it's easy to be wiped out. If they are spread out, then a single move naturally cannot decapitate all of them.
"It's still not as fast as Flying Thunder God..."
Flying Thunder God also has its disadvantages, which is that it requires a coordinate. He doesn't have his own eyes for mind transfer, but crossing worlds consumes too much Mangekyo power. If he were to return once, he wouldn't be able to use mind transfer for at least a year.
The space-time Ninjutsu Flying Thunder God, which consumes Chakra, is certainly more economical and practical. So, if he were to return, he would definitely have to find a way to obtain Flying Thunder God.
"Squeak~ Nagi-aniki (Nagi, older brother), what was that? Eightfold Flash??" A yellow-haired kid peeked out, secretly watching Uchiha Nagi.
"Yes, that day on the train, I saw you use Sixfold Flash, so I was inspired," Uchiha Nagi said.
"Is that so? I really am useless... Ah, boo hoo hoo~~" Zenitsu squatted on the ground, crying with his head in his hands.
Uchiha Nagi: "..."
Seeing this incredibly talented but idiotic boy about to fall into self-pity, Uchiha Nagi reluctantly walked over to comfort him.
Nonsense, if he wasn't incredibly talented, would the retired Thunder Pillar personally teach him?
"Zenitsu, if you want to learn, I'll teach you. You have talents hidden within you that you don't even know about; you just haven't realized them yet," Uchiha Nagi said truthfully. To be able to create a new form on top of Thunder Breathing, which has been passed down for hundreds of years and is almost complete, his talent is definitely beyond question.
"Really? Thank you so much, Nagi-aniki (Nagi, older brother)! Oh, I almost forgot, Miss Shinobu asked me to bring someone over." After Zenitsu finished speaking, he waved to the person behind him.
A person with a ferocious scar on his face and sharp eyes, looking like a delinquent, walked over with his head down.
"Hello, I am a newly promoted Demon Slayer Corps member, Genya Shinazugawa." Unexpectedly, Genya Shinazugawa was very polite to Uchiha Nagi.
"Genya?! I know you, one of the few who survived the selection that day," Zenitsu said curiously.
Uchiha Nagi nodded. "Hello, I am Uchiha Nagi. Did you come to find me specifically for something?"
Genya Shinazugawa lowered his head, seemingly a bit hesitant to speak.
"I want to learn Ninjutsu and Chakra from you..."
"I think I've already handed over the basics of learning Chakra to the Demon Slayer Corps, haven't I?"
Uchiha Nagi himself was busy training various Breathing Techniques every day, and after training, he also had to do research, studying the genes of demons. He really didn't want to take on a student.
Being strangers, he naturally wouldn't spend time teaching others without any benefit... "Is that so~ Excuse me..." Genya Shinazugawa blushed, bowed, and then ran off in a hurry.
"Huh, why did that guy leave after only a few words?" Zenitsu asked, scratching his head in confusion.
"Probably his pride acting up..." Uchiha Nagi understood. Boys care about face the most, and if they can't put aside their pride but still want someone to be their teacher, it simply won't work. Uchiha Nagi always believed in equivalent exchange; if it wasn't an equivalent exchange, then it depended on his mood.
He left, and Uchiha Nagi didn't pay him any mind. If he couldn't be shameless like Naruto, nor sacrifice his life like Sasuke, he naturally wouldn't learn anything.
In the courtyard, he and Zenitsu trained together for over an hour. Zenitsu truly was a genius with extremely high hidden talent. For Thunder Breathing, he only knew the First Form, Thunderclap and Flash.
However, through years of continuous use, he had come to understand something different within the First Form, developing a Two-Flash form. But due to the limitations of his body and dynamic vision, he currently only knew Two-Flash.
"Because your body is still developing, don't rush to develop subsequent techniques. Over-straining a developing body is not a good thing," Uchiha Nagi comforted him.
Zenitsu was still at the age of a teenager, just like Tanjiro. His body still had a long period of development ahead. Appropriate training helps development, but excessive training can leave hidden injuries on the body.
In Uchiha Nagi's opinion, the destructive power and speed of Thunderclap and Flash were somewhat similar to Chidori. He could easily develop from Zenitsu's Two-Flash to Six-Flash, thanks to the powerful dynamic vision of his Mangekyo and his white zetsu cells.
The white zetsu cells continuously strengthened his physique. Now, his Chakra grew day by day, allowing Uchiha Nagi, who had already passed his development period, to undergo a secondary development.
After Zenitsu left, Uchiha Nagi silently turned to the rooftop and said, "Everyone's gone. Aren't you coming out yet?"
[P.S. Fun quiz: Who is on the rooftop?]