And it was precisely because of this outcome that Shennong realized his own shortcomings, and knew that relying solely on his medical ninjutsu would be impossible. It was then that Shennong decided to research Activation Ninjutsu. Researching these things required human bodies for experimentation. Furthermore, Shennong discovered the true reason why Konoha attacked the Sky Ninja Village within Angkor Fortress, which was also why the Sky Ninja Village sought aid from other ninja villages, yet no one came to their assistance.
The Sky Ninja Village began researching the Zero-Tails after the First Great Ninja War. Due to Shennong's usual demeanor, no one was aware of this research. After the First Great Ninja War, the Five Great Nations were established, and each country possessed the Tailed Beasts as ultimate weapons, ensuring a balance of power between them. Although the Sky Ninja Village also possessed great strength, they lacked the ultimate weapon of the Tailed Beasts, thus their position remained below that of the Five Great Nations. With the Tailed Beasts in the hands of the Five Great Nations, obtaining them was extremely difficult.
Additionally, at the beginning of the First Great Ninja War, the Kusagakure, known as the strongest ninja village, and the Amegakure, with strength comparable to the Five Great Nations, both declined. Kusagakure directly became a village, while Amegakure, though still decent, also saw a significant decline in strength, essentially relying on the Hanzo Clan to support it.
(The First Great Ninja War broke out after the establishment of the Five Great Nations and the distribution of Tailed Beasts by the First Hokage. I checked the information, and although it's not entirely accurate, this is how it's set up.)
Seeing this situation, the Sky Shadow of the Sky Ninja Village, although the Sky Ninja Village did not suffer much during the First Great Ninja War thanks to Angkor Fortress, some formerly powerful ninja villages were slowly disappearing. Therefore, to resist the Five Great Nations, the Sky Ninja Village had to possess its own strategic weapon. Since the Five Great Nations held all the Tailed Beasts, they decided to research their own Tailed Beast. It is widely known in the ninja world that the Sky Ninja Village is best at creating various tools, even more so than the Artisan Village. The Artisan Village was merely skilled at creating ninjutsu. One only needed to look at the Angkor Fortress created by the Sky Ninja Village to understand.
One had to admit that the Sky Ninja Village was truly creative and actually found a method: utilizing people's dark hatred to cultivate Dark Chakra, and then transforming it through special methods to create monsters with vast amounts of chakra, which was the Zero-Tails.
Although the Zero-Tails was certainly inferior to the true Tailed Beasts and no match for the genuine ones, the Sky Ninja did not intend for the Zero-Tails to fight other Tailed Beasts when they researched it.
Instead, they planned to use the Zero-Tails as the power source for the Sky City, Angkor Fortress. Tailed Beasts have the ability to generate large amounts of chakra on their own. With the Zero-Tails as the power source for Angkor Fortress, it could fly in the sky forever, and Angkor Fortress's capabilities could be fully utilized. For a long time, although Angkor Fortress was created by the Sky Ninja, due to the immense energy consumption, the Sky Ninja had never been able to fully unleash its power. With an infinite power source, Angkor Fortress could surely unleash its super strength. Its fortress cannon, which consumed almost all of Angkor Fortress's energy for a single shot, could be used continuously. This fortress cannon had never been used since its construction because firing it would leave Angkor Fortress without even the energy to fly. Even if the Sky Ninja Village pooled all its resources, they could not fire more than a few shots.
Once the other research was successful, the fortress cannon could be used infinitely, just like a Tailed Beast. At that time, although the Sky Ninja Village would possess strength exceeding the Five Great Nations, they could turn the Five Great Nations into six. Unfortunately, just as the research on the Zero-Tails was showing promise, the news leaked out, which was the true reason for the Sky Ninja Village's demise.
This was also why Konoha later extensively searched for Angkor Fortress. At that time, the focus on the Sky Ninja Village was primarily due to the Zero-Tails. Since the Sky Ninja Village was destroyed, the other matters were no longer as important.
Precisely because they lost the support of the Sky Ninja Village, the research on the Zero-Tails was shelved. However, Shennong found this research within Angkor Fortress, as well as the sample created by the Sky Ninja Village pooling the strength of the entire village at that time. But by then, there was no one left to continue the research.
In order to retaliate against Konoha, Shennong restarted this research plan. The research for this plan took too long, and Shennong feared he might die before completing it. Therefore, he used his medical ninjutsu to research how he could live longer, giving him enough time to successfully develop the Zero-Tails and then exact revenge on Konoha for the destruction of his village.
This was also why, later, when the remnants of the Sky Ninja launched their revenge against Konoha, he was still in Konoha. This allowed those Sky Ninja to only launch surprise attacks, causing Konoha some losses, but they could not inflict any significant damage. Did you not see how easily those Sky Ninja were eliminated once discovered?
One had to admit that Shennong was quite capable. With only himself, he should not have been able to research the Zero-Tails. However, Shennong took a different approach, thinking about the true Tailed Beast Jinchuriki and decided to find a Jinchuriki for the Zero-Tails.
Shennong's years of traveling through battlefields and treating civilians could be attributed to several reasons. First, he used the unnoticed corpses of orphans on the battlefield to complete his Reanimation Technique. After this was completed, the next step was the Body Rebirth Technique, the same one Orochimaru used. It was precisely for this reason that he collaborated with Orochimaru. Initially, he did not intend to teach Orochimaru the Body Rebirth Technique, but Orochimaru was a very capable individual and managed to research the Body Rebirth Technique using some of Shennong's data, although there was a significant difference between their Body Rebirth Techniques.
Shennong's research on the Body Rebirth Technique primarily focused on the physical body, using chakra to keep the physical body constantly active, thereby achieving longevity, which was very similar to Tsunade's Yin Seal Technique. This Body Rebirth Technique from the movie had also been successfully researched by him long ago, but it lacked the massive amount of chakra required for activation.
Orochimaru's Body Rebirth Technique, on the other hand, was a soul-based Body Rebirth Technique. The physical body was not a concern for Orochimaru, as there were always people being born and growing up. When Orochimaru grew old or suffered a fatal injury, he would use soul transference. Although Orochimaru's physical body, due to Shennong's secrecy, did not learn the physical body Body Rebirth Technique, it possessed extremely strong regenerative capabilities. Orochimaru was only one step away from achieving physical body transference. Considering Tsunade's punch, which could shatter a mountain, Orochimaru was hit by Tsunade so many times when his hand was sealed by the Third Hokage, yet he was unharmed. This shows how powerful his physical body was. After all, Jiraiya once broke six ribs and nearly died from a single punch from Tsunade for peeking at her bathing, which shows how strong Orochimaru's physical body's regeneration was. Of course, this was also because Orochimaru's path was different from Shennong's. If it were physical body activation like Shennong's, he would likely have been knocked down by a single punch from Tsunade.
Another reason for Shennong's presence on the battlefield was to find a Jinchuriki for the Zero-Tails. A Jinchuriki also depended on the compatibility between the person's body and the Tailed Beast. Not just anyone could become a Jinchuriki. If the compatibility was not high, they could not become a Jinchuriki and could not withstand the immense chakra of a Tailed Beast, essentially exploding and dying.
Naruto of Konoha becoming the Nine-Tails Jinchuriki, besides a bit of the Fourth Hokage's personal intention, was also because he couldn't find anyone else. Of course, even if there were such people at the time, the Fourth Hokage would not have agreed. Having his own son become the Jinchuriki was a decision made after years of research on his wife, Kushina. It was all for Naruto to gain greater strength and ensure his survival in this chaotic world of ninjas.
However, the Fourth Hokage sealing the Nine-Tails within Naruto was a very brilliant decision. From the attack of the Nine-Tails to the attack of the masked man, and then the sealing of the Nine-Tails, making such a decision in such a short period of time, the Fourth Hokage truly lived up to his title.
First, the Nine-Tails had to be sealed. From his perspective as Hokage, for the safety of the village, this was necessary. Secondly, the situation at the time was that if Kushina went all out, she could probably seal the Nine-Tails, even if it was a temporary seal. Afterward, they could find a solution. Given Konoha's situation, there wouldn't be any major problems. But regardless of the circumstances, Kushina was doomed. The Fourth Hokage truly loved Kushina, and his promise to Kushina was to protect her. Now that he had failed to protect Kushina, he made the decision to die with her, just as Kushina had said: "Minato, you don't have to go this far." From this point of view, the Fourth Hokage was undoubtedly a good man and a good husband.
Finally, regarding the Nine-Tails attack and the masked man's attack today, although Minato ultimately won, it was a very close victory. This is what is most admirable about the Fourth Hokage. After only one encounter, he immediately identified the weakness of Kamui and then defeated the masked man. This shows how strong the Fourth Hokage's power was. Perhaps some people might not think much of it, just a momentary exchange, how can it show how powerful the Fourth Hokage was?
But in my opinion, the Fourth Hokage's Flying Thunder God Technique Second Step against the masked man can be considered one of the most exciting moments in Naruto. This shows Minato's strength, experience, and judgment are all top-notch. In the world of Naruto, perhaps no one can surpass him. From this aspect, the Fourth Hokage can be considered the epitome of a ninja.
Some people might be exaggerating, but look at Naruto, Kakashi, Guy, and Killer B later, the four of them facing Masked Obito. Before this battle, they already had some understanding of Obito's abilities, and Kakashi's eye was connected to Obito's. Yet, even so, they couldn't defeat Obito after fighting for so long. But the Fourth Hokage only exchanged blows with the masked man once, not only judging the opponent's abilities but also finding his weakness and hitting him. Think about it, since Kamui appeared, who has ever hit him? You can tell how powerful the Fourth Hokage was at that time. Perhaps the Fourth Hokage's combat power was not the strongest in Naruto, but the Fourth Hokage was indeed the most formidable ninja in Naruto.
As for ninjas who prioritize missions, White Fang was forced to commit suicide after abandoning a mission just once. Although there might be hidden reasons, it still shows that a ninja's life can be sacrificed, but a mission cannot be abandoned. If you die without completing the mission, it's a matter of insufficient strength. If you live but don't complete the mission, it's not a matter of strength.
In the world of Naruto, encountering the Fourth Hokage Minato, one could abandon a mission. Minato was the first and only one in the ninja world to do so. Even with the power of Uchiha Madara and the First Hokage Senju Hashirama, they did not receive such treatment. As for whether there will be anyone in the future, I don't know.
Since the Fourth Hokage had decided to die with Kushina, the only thing they worried about was Naruto. Originally, the Fourth Hokage was concerned about this. Even though I am dying, don't forget he is the Hokage. Which Hokage doesn't have direct subordinates? Even Danzo, after being stripped of his power, still had some confidants. Let alone Minato, the Fourth Hokage.
Whether it was in the shadows or in the open, Kakashi was a staunch confidant. Therefore, Naruto's life in Naruto was truly a bit strange. But he is the son of the Fourth Hokage, right? Even as the Nine-Tails Jinchuriki, he wouldn't have drunk expired milk, would he?
Yes, originally Minato wasn't worried, but now with a guy like the masked man, Minato became a bit worried. The protection of others is always by others. That's why the Fourth Hokage sealed the Nine-Tails within Naruto, to give him the ability to protect himself in the future. With Minato's years of research, coupled with the Uzumaki Clan's unique sealing jutsu, he sealed himself, Kushina, and the Nine-Tails within Naruto. This way, if Naruto's strength was not yet strong and he encountered any danger, Minato could still protect Naruto.
So Minato's decision was a bit unfair to Naruto, but it also left Naruto with the power to protect himself. Although Naruto's strength would not be significantly weaker without the Nine-Tails, he would lose the Nine-Tails' recovery ability. In Naruto, it doesn't matter how strong you are, but how durable you are. Think about Orochimaru. No matter how you hit him, he doesn't die. Naruto is also in this state. I can't beat you, but I can wear you out, haha.
In conclusion, the Fourth Hokage Minato can be considered a good Hokage, a good leader, a good husband. I believe no woman would dislike such a man. A good father, although it was a bit difficult for Naruto, but a father must protect his child, right?
Most importantly, Minato made such a decision without much deliberation; it was an instantaneous choice. Who in Naruto has such judgment? Of course, if there was a plan or objective beforehand, that's another matter. But even when Ye Wuji watched Naruto, there was nothing to criticize about the Fourth Hokage Minato. Perhaps later, when facing Madara and Black Zetsu, Minato's performance was a bit lacking, but you have to consider who Madara and Black Zetsu are. It's an absolute power gap, and Minato couldn't do anything about it. Moreover, Impure World Reincarnation cannot truly unleash a person's full strength. With the strength of the four Hokage, let alone Ten-Tails Madara, even if the Sage of Six Paths were alive, what would they fear?
(I've gone off on a tangent, apologies. It's just that when I got to the Fourth Hokage, I wrote down some of my thoughts. If you don't like it, please don't say anything. This is just my personal opinion.)