Uchiha Nagi had never thought that forging a single sword would be so troublesome. He had originally assumed he could just take the materials to the Land of Iron and find someone to forge it successfully.
He hadn't expected that masters capable of forging heavenly materials into swords were now extinct here, or rather, that their craft had been lost. Was Kirigakure to blame?
After creating the Seven Ninja Swords, they had silenced the craftsman, all to prevent any better swords from ever appearing in the world.
"Honestly..."
Uchiha Nagi sighed in frustration. This was their second week in the Land of Iron. During this time, things had been quiet. Nagi had given himself another disguise, this time with yellow hair...
Relying on a single portrait to find him in the vast sea of the black market was like looking for a needle in a haystack. While he wasn't afraid, he disliked trouble.
"Sensei, where are we going next?" Kimimaro asked.
"For now, we'll live in the Land of Iron. They're about to hold a swordsmanship tournament. You should sign up and hone your skills," Uchiha Nagi said to Kimimaro.
"Yes, understood," Kimimaro nodded.
During this time, Kimimaro's strength had improved considerably. Uchiha Nagi still primarily taught him his own Breathing Styles and ninjutsu, telling him to use his Shikotsumyaku as little as possible. As for Nagi himself...
He glanced around the capital city of the Land of Iron. In this entire country, there was only one person Nagi could challenge to a sword fight: Mifune.
Samurai were a single-minded bunch. In his youth, Mifune had crossed swords with Hanzo. Hanzo had not only bested him in swordsmanship but had also, without any martial honor, coated his weapon with poison.
Afterward, whether out of shame or moved by Mifune's samurai spirit, Hanzo had left the antidote and spared his life.
So many years had passed. Mifune's swordsmanship had likely progressed by leaps and bounds, reaching a pinnacle of mastery, no less than Kakashi's father had in his day.
But what level he had actually reached was unknown. If Uchiha Nagi wanted to test his own swordsmanship, he just had to find him here in the Land of Iron.
Beyond that, he needed a large amount of capital. Researching White Zetsu's cells and experimenting on his own body were both money-burning endeavors.
He returned to the house he was renting. It was in the center of the Land of Iron's capital. Although the rent was a bit steep, it was safe. Moreover, the country's principle of neutrality meant that ninja were not welcome here. It would be impossible for Root or Anbu to send a few squads in; that would be tantamount to a declaration of war.
"Kimimaro, even in the Land of Iron, you must not let your guard down. Don't exhaust yourself completely during training; always reserve some strength for emergencies."
"Yes, Sensei," Kimimaro nodded, then picked up his newly bought sword and began to train with Yukihime.
During this time, whenever he had a spare moment, he had taught Yukihime Wind Breathing and found that her affinity for it was quite good. Although she had been pampered and had never fought or killed anyone, Yukihime's progress was not slow.
Uchiha Nagi nodded at them, then went into the basement. He had many things to do.
Descending into the basement, which was a dozen meters deep, Uchiha Nagi activated a barrier to prevent any accidents. Then, he released the wild White Zetsu he had captured earlier.
Released from the sealing scroll, the White Zetsu remained dazed, its eyes wide. It was under Nagi's genjutsu, in a continuous state of unconsciousness.
He had interrogated it for some information before. Unfortunately, this was just a clone, so it didn't have much valuable intelligence. He knew more about the Land of Rain than it did...
Uchiha Nagi took out a test tube and inserted it into the White Zetsu's spinal column, drawing out some of its bone marrow...
"Aaaargh—"
The intense pain woke the White Zetsu from its deep genjutsu-induced coma. It looked at Uchiha Nagi in terror. This man was a devil. The experiments he had performed on it these past few days were terrifying. Drawing blood and marrow without any anesthesia... he might as well just kill it.
"Go to sleep. It won't hurt when you're asleep," Uchiha Nagi glanced at it. The White Zetsu's eyes glazed over, and it once again entered the world of genjutsu.
After drawing the sample, Uchiha Nagi placed the tube of bone marrow into a green test tube containing a prepared solution.
This wasn't just a nutrient solution; it contained other substances meant to neutralize the rejection between his Uchiha bloodline and the White Zetsu cells. One of these was a peculiar substance he had extracted and cloned from Shinazugawa Genya's body.
It was like with Shin in the Naruto story. Shin's genes were very special; he could accept any kekkei genkai transplant without rejection. So Orochimaru had used his cells as a harmonizer to create an arm for Danzo. That arm, a fusion of Hashirama's cells and Sharingan, maintained a miraculous balance between the two.
This allowed Danzo to not only have Shisui's Mangekyo in his eye socket but also a whole arm full of three-tomoe Sharingan. If it had been Kakashi, he would have been drained into a husk long ago.
Now, Uchiha Nagi, like Orochimaru, had found a treasure trove: the cells of Shinazugawa Genya. He could eat demons, digest their cells for his own use, and even unleash their Blood Demon Arts.
Uchiha Nagi used his cells as a harmonizing agent, and it was unexpectedly successful. As long as he added Genya's cells to modify the White Zetsu cells, he could inject them into his own body and absorb the digested cells.
Note, digested.
But the ratio had to be very precise. One milligram of Genya's demon-eating cells could digest and convert 0.8533 milligrams. Once Genya's cells had assimilated the White Zetsu cells, they were ready for consumption. However, after careful observation, Nagi found that consumption wasn't as effective as direct injection.
So, he extracted the White Zetsu's bone marrow, neutralized it, and injected it into his veins, acquiring Wood Release cells without any side effects.
"The combination of the two can grant the power of all creation..." Uchiha Nagi clenched his left fist, then quickly produced a branch, which then grew into a large tree...
This was Yamato's Wood Release. He had been injecting White Zetsu's bone marrow for a few days and could already use it. But it was only good for ornamental purposes. In a fight, it was useless...
Wood Release was indeed useful for suppressing Tailed Beasts, but in other areas, it was unremarkable. Just look at Yamato.
It was less that Wood Release was powerful and more that Hashirama Senju had so much chakra that the quantity produced a qualitative change, leading to some misunderstandings. That's why Orochimaru didn't continue down the dead end of fixating on Hashirama's cells in his later research.
However, if Orochimaru had successfully taken over Sasuke's body, he probably would have transplanted some of Hashirama's cells into himself. After all, he had already successfully done it once for Danzo.
After the transplant, Danzo not only recovered from his injuries, but his strength also didn't decline even after several decades.
After lying quietly in the basement for an hour, feeling that the White Zetsu cells injected into his body had been more or less digested, Uchiha Nagi packed up his things and returned to the surface.
The White Zetsu had to be sealed in a storage scroll and carried with him at all times. Other research equipment could be bought again if lost, but if he lost the White Zetsu, it was gone for good. And he didn't know how much longer this particular Zetsu would last.
The various nutrient solutions needed for cloning cells all cost money. The bounty from Asuma hadn't even warmed his pocket before Uchiha Nagi had already spent half of it.
Returning to the surface, Uchiha Nagi sensed the chakra within his body. A strange feeling he couldn't quite describe came over him. His chakra was transforming.
"Wood Style: Deep Forest Emergence..."
He clapped his hands together, and the small trees in the courtyard began to sway and grow. In a short while, the entire courtyard was covered in trees.
Uchiha Nagi shook his head. Just greening the courtyard and growing a bunch of trees was useless. A single fire jutsu would burn it all away.
It was only useful if he could create a primeval forest with trees dozens of meters high, a Deep Forest Emergence that could attack people.
"Time to go make some money. And while I'm at it, I'll ask around for a master who can forge special swords..."
He only had that one small piece of meteorite, which definitely wasn't enough. And chakra metal was ridiculously expensive; a tiny piece cost hundreds of thousands. Fortunately, Nagi had looted Asuma's weapons from his corpse. He could melt them down and use them later.
The ninja world as a whole was still an agricultural society. Farmers still tilled the fields with their hands and feet; Naruto's team had even taken on a mission to help with farming. In such an environment, buying research drugs and equipment was undoubtedly a money-burning affair. No wonder the proud Orochimaru had established the Village Hidden in the Sound.
Having the financial and material support of a small country was better than struggling to gather resources and make money all by himself.
After giving Kimimaro some instructions, Uchiha Nagi left with his heavily chipped Nichirin Blade.
"The Nichirin Blades from the Demon Slayer world are indeed good, top-quality even. But they're still not enough..."
He shook his head. He didn't know how much longer this sword would last. Making money was the priority.
Three days later—
"Please, spare me..."
"Sorry, I need the money."
Pfft!
With a single, merciless slash, Uchiha Nagi finished him off. He wouldn't spare someone just because they begged for mercy. Ninja were people with blood on their hands; none of them were innocent.
After killing him, he sealed the body in a storage scroll and headed to the next black market.
Recently, the black markets in the Land of Fire had been ruthlessly purged by the grieving Third Hokage. The black market merchants were terrified, and many could only flee to the smaller countries to take on missions and collect bounties.
Just as he was about to enter a black market outpost to exchange his prize for cash, a man completely wrapped in a black robe brushed past him. He had emerald green eyes, a cold aura emanating from his body, and a terrifying amount of chakra that screamed, Stay away from me, or die...
Hm?!
Uchiha Nagi, who had been about to enter the outpost, suddenly had a flash of inspiration. He seemed to have realized something. He immediately turned and tentatively called out, "Kakuzu?"
The man in the black robe also jolted, then turned around, a look of pleasant surprise on his face. "Uchiha Nagi?!"
"It really is you!" they both said at the same time.
Uchiha Nagi had recognized him, of course, because of his peculiar eyes. Someone with such a vast amount of chakra, with emerald green eyes, who liked to hang around black markets—the probability of it being Kakuzu was extremely high.
Uchiha Nagi subconsciously asked a question he had always been curious about: "Why is there no red cloud on your black robe?"