In the end, the Fourth Raikage, A, left. After careful consideration, Nagi had decided not to make his move within the borders of the Land of Iron. Killing A was possible, but it had to be done in the Land of Lightning, or somewhere else. If it happened in the Land of Iron, the enraged Land of Lightning would surely send a massive army in retaliation, and the Land of Iron would face utter annihilation, just as the Land of Whirlpools had at the hands of the Land of Water.
It was all too easy for one of the Five Great Shinobi Countries to crush a smaller nation. Especially now, with no Great Ninja War to keep them in check, if the Hidden Cloud truly made a move, the Land of Iron was doomed.
What would happen then?
Some of the enraged samurai, not knowing the sheer difference in power, had gone after A. The rest had stayed behind. Nagi shook his head. Without Mifune, the Land of Iron was just scattered sand. Without a single Kage-level warrior, they didn't stand a chance.
He vanished with a teleport. He needed to check if Kimimaro and the others were alright. Now that he had captured a Tailed Beast, it was time to forge his own ninja blade.
"Sensei! Are you alright?"
"Nagi-nii, are you okay?"
Kimimaro and Yukihime rushed over, overjoyed. To Nagi's pleasant surprise, they had someone with them: the old swordsmith, Watanabe. It saved him the trouble of having to look for him.
"Watanabe-san, so you were here," Nagi said, having used the kunai he'd given Kimimaro as a marker to teleport to their location. He hadn't expected to find the swordsmith Mifune had invited here as well.
"That I am," the old man said. "The Fourth Raikage, A, went mad for some reason. Suddenly barged into the Land of Iron and attacked Mifune's home. This old man heard him demanding that Mifune hand over these two, so while they were fighting, I took the chance to slip away and come notify them."
"Mifune-san is dead. He died at the hands of the Raikage," Nagi said. "The Raikage came for me. I'm the one who got him involved."
Nagi didn't hide the truth. He confessed that he had stolen the Land of Lightning's Island Turtle first. The Island Turtle's importance to the Land of Lightning was no less than that of a Tailed Beast. After all, not every jinchuriki could convince their Tailed Beast to willingly hand over its chakra to become a perfect jinchuriki. The Island Turtle, however, bridged that gap. It allowed a jinchuriki to become perfect even without the Tailed Beast's consent, so its importance to the Land of Lightning was unquestionable. There was a reason the Fourth Raikage had gone on a rampage looking for him.
"But I will avenge Mifune-san's death one day. After A leaves the Land of Iron, I will go to the Hidden Cloud to find him. But the most pressing matter right now is to forge my sword."
Nagi tossed aside his scabbard. The fine steel longsword he had been using had shattered in the fight with the Fourth Raikage. He had already discarded it.
"Sigh..." Watanabe opened his mouth, but in the end, all that came out was a sigh. "This is the way of the ninja world. You take revenge on me, I take revenge on you. There will never be a day of peace. But this old man is just a swordsmith. If true peace ever did come, I'd probably be out of a job. Isn't that ironic?"
Nagi thought for a moment. "Peace will come one day. As long as someone can unite the entire ninja world, there will be no more war or strife. Watanabe-san, the Tailed Beast you asked for, I have it ready. When do you think you can start forging my sword?"
Hearing this, Watanabe's eyes widened to the size of bronze bells. "What? Say that again! You really brought back a Tailed Beast? Did I hear you right? Which one?"
Nagi smiled. "That's right. A Tailed Beast. The Three-Tails, from the Hidden Mist."
The old man's mouth hung open. He knew that the current Three-Tails was inside the body of the Fourth Mizukage. If Nagi had captured the Three-Tails, didn't that mean the Fourth Mizukage was...
"It's better for your own safety if you know less about the specifics, Watanabe-san. News will get out eventually."
"Right, right. This old man was being presumptuous. What am I asking that for? Anyway, I'm just a swordsmith. I don't care about anything else. I have everything you need ready. I carry it with me." Watanabe patted a storage scroll on his hip. "Chakra metal, books on sealing jutsu, and some other supplementary materials are all in here. Now we just need to build a furnace, carve a stable enough sealing formula on it to prevent it from exploding, and we can get started."
"Heh, I've already prepared a place. Let's get going," Nagi said excitedly.
"What place?"
"The Island Turtle."
"..."
Three days later, on the Island Turtle—
Under Nagi's control, the Island Turtle had already sailed to the vicinity of the summoning beast island. He had also collected water from the island to use for quenching the blade, a move Watanabe had enthusiastically praised. According to his observations, the summoning beast island was incredibly rich in energy, making its water excellent for quenching.
They ultimately decided to use the secret chamber on the Island Turtle for the forging. After all, it was a place that could confine and control even a rampaging Tailed Beast, which saved Nagi the trouble of building a furnace from scratch. Under Watanabe's direction, Nagi made a few modifications to the sealing chamber, and it was ready to be used. Honoka also contributed a great deal, reinforcing the chamber's seals.
Only Yukihime stood off to the side, sulking. She couldn't help with anything, and she watched as Honoka and Nagi worked closely together...
"Vixen," Yukihime muttered under her breath.
"Yuki-nee, what did you say?" Kimimaro asked from the side, having seemed to catch her mumbling.
"Oh, nothing. By the way, Sensei told you to pick one of the summoning beasts on the island. Have you chosen one yet?"
Kimimaro scratched his head. "There are some with good combat power on the Island Turtle, and on the summoning beast island, too. But I've thought about it, and I think I'll just be like Sensei and make a contract with a giant eagle. Besides, Sensei's eagle has already laid eggs..."
Yukihime asked curiously, "Why an eagle? Are the others no good?"
"Sensei said that there are very few ninja in the world who can fly. If I choose an eagle, I can run away if I can't win..."
"..."
Inside the mountain behind the Waterfall of Truth, in the secret chamber, the three of them were ready.
Nagi nodded at Watanabe and released the Three-Tails, which was under the control of his Mangekyo. Its massive body appeared in the cave.
Although Watanabe and Honoka were prepared, they were still taken aback by the sheer size of the Three-Tails. The aura and chakra radiating from its body told them that this was an ancient, monstrous beast, and that humans were as insignificant as ants before it.
Honoka trembled slightly. "Nagi-nii, is this... a Tailed Beast? It won't suddenly wake up, will it...?"
In her perception, the Tailed Beast's chakra was incredibly evil and unimaginably vast. She couldn't fathom how humans could subdue such a monster.
Nagi smiled. "Don't worry. See its eyes? Before the Mangekyo, a Tailed Beast is nothing more than a pet."
Watanabe swallowed hard and nodded. "Then let's begin. Nagi, my brother, take out your materials. This old man will forge a famed blade for you today, a divine weapon whose renown will be no less than that of the Seven Ninja Swordsmen."
Nagi nodded, his heart also pounding with excitement. He took out the materials he had prepared: the sun ore from the world of Demon Slayer, the meteorite from the Village Hidden among the Stars, Zabuza's Executioner's Blade, and his own broken Nichirin Blade. Besides those, there were other supplementary materials, such as precious metals that conduct chakra, chakra metal, fine iron ore, gold, and some charcoal...
According to Watanabe, it was better to be overprepared. During the forging process, it was hard to gauge how the metals would fuse under the immense pressure and hammering of the Tailed Beast's chakra. The higher the density, the smaller the volume. If that happened, the sword would be too small. He couldn't have Nagi going into battle with a sword the size of a kunai. So, they had prepared as much metal as they could to serve as the body of the blade.
The main core would be the meteorite from the Village Hidden among the Stars, with its immense energy. After it was melted down, it would be placed in the hilt of the sword. That way, even if the blade was damaged in the future, it wouldn't affect its ability to be repaired. If the hilt itself was damaged, well, Nagi would have either had his hand cut off, or he'd be dead...
A furnace had been set up in the secret chamber, connected to a sealing formula array. In the center of the array stood Honoka, who was proficient in sealing jutsu. Watanabe was an amateur when it came to sealing; if he were in control, he would probably ruin the sword. So, Honoka, an Uzumaki who was an expert in the art, would control the size of the fire. Nagi, meanwhile, would control the Three-Tails, supplying chakra to the furnace.
The poor Three-Tails. It had been under Obito's genjutsu for so long, and just when it finally broke free, it had fallen into the genjutsu of another Uchiha.
"Alright, let's begin." Watanabe said, after placing the various materials into the furnace. He nodded at Nagi.
"Okay."
Nagi opened his Mangekyo and commanded the Three-Tails. Standing in the center of a sealing array, it began to pour out its chakra.
A short while later, the immense chakra, converted by the sealing formulas and the array, began to flow into the furnace, melting the metals inside.
Watanabe placed his hand on a switch, feeling the degree to which the metals inside had melted.
"Good, don't stop! The sun ore has already melted, and the Nichirin Blade and the fine iron ore too..." the old man said excitedly. "Now all that's left is the meteorite. The energy inside it is too great. Once it melts, the energy will leak out. That's where the sealing jutsu comes in. We have to lock its energy in and fuse it into the sword blank..."
The secret chamber shone with a seven-colored light. The formulas on the walls were all connected to the furnace, incredibly stable. Once activated, not even a Tailed Beast could break out of this place.
And so, they continued the forging process for several hours...