Chapter 62: Ancient Martial Arts of This World

"Senpai..." On the road, the C-Rank Demon Slayer, Heiji Hattori, hesitated before asking in a low voice.

"About my injury... could you please not tell anyone...?"

After speaking, he lowered his head, his face beet red. If word of something like this got out, he'd probably be laughed at by his Demon Slayer Corps colleagues for the rest of his life, becoming a running joke for their daily banter. That, for him, would be a scene of utter social mortification...

"Huh?! What did you say?" Uchiha Nagi looked up, giving Heiji a deadpan fish-eyed stare, a puzzled expression on his face.

"Ah, it's nothing, nothing! It's best if you don't remember, hahaha, yes, yes, it's nothing at all," Heiji said cheerfully.

This mission could be considered a relatively successful completion, despite the one sacrifice.

Nagi was currently perusing some historical accounts of this world. Although it wasn't as developed as the Ninja World, many wondrous things had appeared here. For example, Muzan was once a frail and sickly human who remained so into adulthood. Then, the doctor treating him somehow procured a miraculous medicine that directly altered his constitution, making him a healthy human.

Unfortunately, the medicine had a side effect: he couldn't be exposed to sunlight. Muzan, who had long suffered from illness, had already lost any human sense of gratitude. When he discovered he couldn't consume human food but could grow stronger by eating humans, he completely degenerated, even brutally killing the doctor who had cured him.

However, while this world lacked Chakra, extraordinary powers like battle aura and sword arts did exist. After Muzan began creating subordinates to find a way to overcome his weakness to sunlight, many righteous martial artists and swordsmen possessing these extraordinary powers started to hunt down these man-eating demons.

But why they all gradually disappeared later, leaving only swordsmen who used Breathing Styles—that is, the Demon Slayer Corps—was an easy answer to deduce. Martial artists had no advantage against the immortal demons; even if they destroyed their brains and hearts, the demons could still fight. The same went for swordsmen initially.

Later, perhaps a swordsman's blade was forged from sun ore, and it was discovered that severing a demon's neck with such ore could eliminate them. Thus, a second method of killing them, besides sunlight, emerged. Gradually, various martial artists began to decline, replaced by swordsmen wielding Nichirin Blades. Then, through a historical accident, Yoriichi Tsugikuni, born innately with access to the Transparent World, created the strongest Breathing Style: Sun Breathing.

He then taught Sun Breathing to all demon-hunting swordsmen. But the requirements for Sun Breathing were too demanding, so gradually, some swordsmen of great wisdom created various other Breathing Styles derived from it.

What Uchiha Nagi was currently reading about were legends of martial arts schools that existed before Breathing Styles appeared. The reason he could copy Akaza's techniques was precisely because Akaza used human martial arts. The difference was that without a powerful physique and strong recovery abilities, forcibly using the later forms would have side effects similar to Rock Lee opening the Fourth Gate right at his debut.

Even so, Uchiha Nagi was still very fond of the martial arts of this world. To master the strengths of a hundred schools could lead to one's own enlightenment.

Of course, in this time period, even firearms had appeared, so those martial artists had faded even further into obscurity. Uchiha Nagi read on, interested in some of this world's history.

For example, a demonic blade called Manyuanmaru had once appeared in this world. The user of this blade could make three wishes on it, all of which had to be used for battle, guaranteeing victory each time. After the three wishes were used, the wisher would suffer a backlash and die a horrible death.

Also, before Muzan's appearance, the martial artists here had flourished, with a hundred schools of thought contending. Among them was a forbidden technique called "Celestial Ladder to the Other Shore: Soaring Dragon Ascension." This was a combat technique that utilized the opponent's momentum, guiding it through Five Elements Eight Trigrams Footwork to create a tornado-like attack to defeat the enemy. More powerfully, it was created for use on the battlefield: the more people and the stronger the killing intent and momentum, the more terrifying its destructive power.

There was another art, similar to a monstrous strength fist, called "Explosive Acupressure Point Strike." Using a single finger, one could gather bodily energy and strike, capable of shattering mountains and crushing stones.

"Interesting. If these things can be found, that would truly be interesting." Uchiha Nagi looked at the book with keen interest. It had been brought from the Ubuyashiki Estate, so the records within were genuine, though the arts themselves had been lost to time. Not just these, even Sun Breathing had been lost to the Ubuyashiki family.

A faint smile played on Uchiha Nagi's lips. It didn't matter if they were lost, as long as he knew who created them. Because the Ninja World had a jutsu called Edo Tensei.

Did the Second Hokage truly invent over a thousand forbidden jutsu himself? With his intellect, wouldn't he have made deals with the powerful deceased he resurrected, learning their forbidden techniques?

Therefore, Uchiha Nagi had already made up his mind. When he returned to the Ninja World, the first thing he would acquire was Edo Tensei. Then, he would reincarnate the founder of Demon Slayer's Sun Breathing, learn everything from him, and then learn from others. If he were to reincarnate the powerful figures from the Ninja World's wars, they would be suspicious and wouldn't teach him their forbidden jutsu. It was better to seek out people from this world.

However, how to obtain the improved Edo Tensei 2.0 version from that snake Orochimaru, and Kabuto Yakushi's later 3.0 version, was a difficult problem. That venomous snake Orochimaru was not an easy person to deal with. One careless move, and ending up double-crossed like the Fourth Kazekage was a common occurrence.

"Um, I'm planning to go train with Gyomei Himejima-san. Do you want to come along?" Uchiha Nagi asked Heiji.

"Eh? Can I, Senpai? That would be great! I'd be so grateful to go with you!" The C-Rank cannon fodder, Heiji Hattori, beamed with delight.

"Then let's go together."

Upon returning to the Butterfly Mansion, Nagi learned that after a period of his special training, Inosuke and the other two had formed a team and gone out on a mission with Tanjiro.

Uchiha Nagi directly approached Ubuyashiki to explain the situation. Ubuyashiki had also written to Gyomei Himejima, who had agreed.

"Eh? Nagi-kun, you've returned safely! That's wonderful," Shinobu Kocho said with a joyful expression upon seeing Uchiha Nagi.

"Mm, it was just a fellow with some peculiar abilities, not very strong, so it was resolved quite easily," Uchiha Nagi also smiled and nodded. "Next, I plan to go to Gyomei Himejima-san's place to train for about half a month to a month, and then I'll return to my homeland to deal with some matters."

"Is that so? Please wait a moment, I'll get you some healing medicine," Shinobu Kocho said, and with a swoosh, she disappeared. When she reappeared, she was holding a small package.

"Thank you, Shinobu-san." Uchiha Nagi didn't stand on ceremony, accepting it with a slight smile.

"Mm, I wish you success in your training. Oh, and I should thank you too. I think I'm starting to get a feel for Chakra. I've managed to sense a tiny bit of it these past few days," Shinobu Kocho said with a smile.

"Mm..." Uchiha Nagi nodded, unsure what to say next. After a moment's pause, he finally thought of something. "Keep up the good work. Well, I'll be going then..."

"Heehee..." After Uchiha Nagi left, Shinobu Kocho covered her mouth and giggled.

After bidding farewell to Shinobu Kocho at the Butterfly Mansion, Uchiha Nagi headed towards Gyomei Himejima's training ground, located in a large mountain range with a waterfall.