Starting with the Uchiha clan, they began cultivating demonic arts.

Chapter 120 The Soul Refining Method and the Primordial Treasure Box

Having dealt with the prisoners of Hozuki Castle, Uchiha Hiyu gained over a hundred more black wisps for sacrifice, all of them of high quality.

The grass ninja were also very happy, especially the lord of Hozuki Castle, Muwei, because more than half of the primordial pills refined by Uchiha Hiyu were given to this lord who had surrendered the castle.

Unfortunately, he was too happy too soon. With a single Divine Transmission Technique, Uchiha Hiyu completely controlled the Lord of Hozuki Castle, giving him absolutely no chance.

In fact, Wuwei's strength was almost the strongest among the original Grass Ninja. After consuming a large number of high-quality Origin Pills, he improved faster than the three Grass Ninja leaders and possessed strength comparable to the Third Hokage.

The current Third Hokage is around 50 years old. While he may not be invincible, he is much stronger than he was in later stages of his life, and can be considered a strong figure among Kage-level shinobi.

With the addition of Wuwei, the Grass Ninja now possesses a top-tier Kage-level ninja, three strong mid-level ninja among the three Kage-level ninja, over a hundred Jonin, nearly a thousand Chunin, and over 2000 ordinary Genin.

Except for the genin stage, where it lags behind the great ninja villages, the Grass Ninja Village is no less powerful than the five great ninja villages at any other stage, and is even much stronger than most ninja villages.

Furthermore, all the major ninja villages are either still recovering from a major battle and suffering heavy losses, or they are still in the midst of a chaotic war. It can be said that the Grass Ninja has become a significant force in the entire ninja world.

At least... this force already has enough confidence to capture other ninjas.

Even the five great ninja villages would treat such a powerful force with caution, and they would not dare to take action against the grass ninjas before the war ends.

As for whether several ninja villages will simultaneously attack the Grass Ninja, that's none of Uchiha Tou's business.

In the end, these grass ninjas were just tools for Uchiha Hiu to harvest sacrifices and artificially cultivated medicines; it wouldn't matter if they all died.

Then, Uchiha Touyu turned his gaze to the so-called Box of Bliss, raising an eyebrow slightly.

"This box... is interesting!"

The Box of Bliss is said to be a treasure created by the Sage of Six Paths, and there are absurd rumors that whoever opens the Box of Bliss can have a wish granted. However, Uchiha Touyu saw at a glance that this box has little to do with chakra.

Although the box was also entangled with a large amount of energy, that energy was filled with a dark and bloody aura. Judging from the demonic arts he cultivated, the energy entangled with the box was more likely to be pure resentment than anything like dark chakra.

"It feels like good material for making magical artifacts. Come to think of it, I don't seem to have any good magical artifacts yet."

The Kusanagi Sword is quite powerful, but in the end, apart from a burst of evil energy, it's just a sharp and sturdy weapon, far inferior to those magical treasures and artifacts.

The Devouring Demon Art, inherited from the Shrouding the Heavens Technique, does contain some knowledge about weapon crafting. However, the weapon crafting techniques of the Shrouding the Heavens Technique are only for fun. Apart from the natal magic treasures they create themselves, they are completely incomparable to the weapon crafting techniques of other cultivation worlds. Not to mention that the knowledge that Uchiha Touka obtained is also very incomplete.

Furthermore, Uchiha Touyu was unable to cultivate the secret realm techniques, so he couldn't forge his own natal magic weapon at all. Moreover, the best materials for the weapon-refining secret techniques in the Devouring Heaven Demon Art were actually the physical bodies of people with special physiques, while the methods for refining various rare and precious treasures were quite ordinary.

Not to mention that there are no rare and precious treasures in the ninja world. The Box of Bliss is completely different from the real rare and precious treasures. Who knows what kind of thing will be refined using the Devouring Demon's power?

With this in mind, Uchiha Touyu made up his mind to extract some knowledge about weapon crafting from the Book of Demonic Path Inheritance and make the entire Box of Bliss his own.

He also happened to have harvested several thousand ninjas in the Grass Ninja Village, so there was plenty of black energy offerings.

As the black aura on the altar slowly dissipated, the Book of Demonic Inheritance vibrated twice more, transmitting two messages to Uchiha Touyu.

This time, Uchiha Touyu's request was to maximize the use of the Elysium Box method, but the Book of Demonic Inheritance gave him two inheritances.

One method is a magic weapon forging technique called the Hunyuan Treasure Box, and the other is a soul-refining technique.

The name "Hun Yuan Treasure Box" sounds impressive, but it is actually a demonic artifact. As for its effects, it can be seen as an enhanced version of the Blood Pool.

The Blood Pool can refine the bones and blood of others to improve one's bloodline, while the Hunyuan Treasure Box can refine bones, blood, and soul completely. Its effect is not just to improve the bloodline, but to comprehensively enhance chakra, physical talent, and soul strength.

To put it simply, it's a fully automatic alchemy furnace, except that the materials it needs are all flesh and blood, preferably alive.

The pills produced there are far superior to those from the blood pool. If an ordinary ninja were thrown in, he could extract his soul essence, physical blood and qi, and his own chakra.

"This truly lives up to its reputation as a book of demonic inheritance; eight out of ten inheritances teach you how to eat people! But what I wanted was a magical artifact to increase my combat power, so why did I get this thing?"

Indeed, Uchiha Touyu has now discovered that his methods of cannibalism have become increasingly sophisticated. From the Spirit Binding Technique to the Spirit Devouring and Blood Refining Secret Technique, then to the Heaven Devouring Demon Art, and finally to the Primordial Chaos Treasure Box and the Soul Refining Secret Technique, each one is a unique skill for cannibalism.

The Soul Refining Secret Technique and the Spirit Consumption Technique of the Spirit Binding and Condemning Generals are quite similar. They are secret techniques from the Soul Clan of Doupo Cangqiong, the same secret techniques used by the Soul Palace with their raucous laughter.

The reason this soul-refining secret technique came about is because the Box of Bliss stores a massive amount of souls.

Now, Uchiha Touyu is increasingly convinced that the Box of Bliss has nothing to do with the Sage of Six Paths, because according to his perception from the Soul Refining Secret Technique, the large box in front of him contains at least a million souls!

Moreover, these souls are not those of ordinary people; they must at least be at the ninja level to be included in the box in front of us.

It should be noted that during the Fourth Shinobi World War, the five major ninja villages plus various smaller ninja villages combined only produced an army of 80,000 ninjas, and that was after more than a decade of peace.

Even if you estimate the upper limit high, the number of ninjas existing in an era at the same time cannot exceed 20. Theoretically, the Box of Bliss must have buried five generations of ninjas to collect so many souls.

The actual number is definitely more than that. You have to know that the huge expansion of the number of ninjas only happened after the establishment of the Five Great Ninja Villages. Before that, almost all ninjas existed in the form of clans, and there were at most tens of thousands of them throughout the entire ninja world.

The Sage of Six Paths founded the Ninja Cult and passed on his chakra to the world only a thousand years ago. No matter how you calculate it, the Box of Bliss could not have collected the souls of nearly a million ninjas in a thousand years.

"Maybe this thing existed many years before Kaguya, otherwise it couldn't have devoured so many souls. And it seems to have the style of an Onmyoji or similar system."

The practice of devouring souls, absorbing resentment, and creating a being capable of sensing hostility is extremely rare in the chakra system, but it is considered basic in Yin-Yang techniques.

However, Uchiha Tou quickly stopped thinking about which deity created the Box of Bliss. Instead, he sat cross-legged on top of the box and began to refine it.

Although there is no systematic cultivation method, the chakra within Uchiha Hiyu's body has undergone a great change in nature after being forged by many secret techniques. It is somewhat close to the legendary magic power, and at least it can be used to refine and forge the Box of Bliss.

As his chakra slowly permeated the large box beneath his feet, Uchiha Hiyu also began to circulate the Soul Refining Technique. The millions of souls stored inside the Box of Bliss were gradually being refined into soul energy.

There are millions of souls, but their quality is not high. The main reason is that too much time has passed, and the energy inside the souls has been severely depleted.

Moreover, the Box of Bliss was filled with malevolent energy, and the souls stored inside were severely tainted, containing numerous impurities, almost 99% of which were resentment, leaving only a trace of pure soul energy.

Uchiha Touyu's soul-refining method comes from the Soul Clan in the Doupo world. It can completely eliminate resentment by repeatedly refining it. However, while completely eliminating resentment, waste is inevitable.

Especially those souls imprisoned in the Box of Bliss, filled with resentment, may seem numerous, but after being completely refined, not even one-thousandth of their pure soul energy remains.

The soul energy of about several hundred people is not weak; at least, Uchiha Tou's soul energy is roughly the same as that of several hundred people.

Chakra isn't even a complete cultivation system; it's more like a superpower. It only increases with the growth of the body and mind, and there's no specific cultivation method.

Therefore, even so-called Kage-level powerhouses only have soul energy that is at most ten or dozens of times stronger than that of ordinary people, thanks to the nourishment of chakra.

Uchiha Touyu's powerful soul energy was boosted by a host of demonic techniques, especially the Soul Binding General which devoured souls and the Devouring Heaven Demon Art which absorbed essence, energy, and spirit, greatly enhancing Uchiha Touyu's foundation.

However, neither the Spirit-Binding and Commanding Generals nor the Heaven-Devouring Demon Art are techniques specifically designed to devour and increase the size of the soul.

After the Spirit-Binding General devours a soul, what increases is the innate Qi, not the soul energy, and the conversion is only one in a hundred.

As for the Devouring Heaven Demon Art, its greatest effect is to change one's physique and merge all bodies into chaos; the increase in soul energy is merely a side effect.

Therefore, although Uchiha Tou's soul energy was not weak, it was not particularly high either. Compared to ordinary Kage-level ninjas, it was a precipitous improvement, but compared to his physical foundation, it was far inferior.

However, this time there was a chance to make up for it. While refining the Bliss Box beneath his feet, Uchiha Hiyu absorbed the soul energy within the box, feeling his soul and body enter a strange state.

He didn't know how much time had passed, but he felt as if he had become extremely light. With a light leap, he broke free from a restraint and floated in mid-air.

Looking down, Uchiha Touyu immediately saw his physical body sitting on the Box of Bliss. Only then did he belatedly realize that his soul had left his body.

Uchiha Touyu had previously practiced a secret technique called Spirit Transformation Technique. Even though he didn't pay much attention to it at the time, he easily mastered it thanks to his extraordinary foundation.

However, this ninjutsu was not very effective against Uchiha Touyu, whose physical body was completely defenseless after his soul left him, which is why he had never used it.

"However... I'm not currently in a state of spiritual transformation... my physical body is still refining the Box of Bliss below!"

"What is this thing? Is it the legendary state of 'no thought, no law'?"

After using the Spirit Transformation Technique, the ninja's physical body lost all sensation, almost like a vegetable. However, Uchiha Hiyu could clearly feel that his physical body was still being refined in the Paradise Box below, so his current state was obviously not the Spirit Transformation Technique.

Not to mention, Uchiha Hiyu could also sense that his soul did not contain any chakra, which was completely different from the energy shell formed by chakra when he used the Spirit Transformation Technique.

Although he didn't know what state he was in, Uchiha Touyu could sense that it wasn't a bad thing.

A moment later, Uchiha Tou felt a suction force coming from below his body. In an instant, his soul returned to his body, and he could also feel that his soul seemed to have become much more stable.

After absorbing a large amount of soul energy, although Uchiha Touyu could feel his perception, reaction and chakra control abilities improving by leaps and bounds, he also had a light and floating feeling. After this change, however, he felt a sense of groundedness.

Letting out a long breath, Uchiha Touyu revealed a hint of joy. In fact, while Uchiha Touyu's strength had been improving by leaps and bounds, it was also fraught with hidden dangers.

After all, so-called demonic cultivation methods always have the drawback of being impatient for quick success and instant benefits. And the Uchiha bloodline and chakra system are not exactly a solid foundation of power. On the contrary, they can be said to be the most demonic of the demonic paths. Naturally, Uchiha Tou's cultivation also felt a bit like walking a tightrope.

Although his cultivation has improved rapidly, his foundation is by no means solid. It is only slightly stronger than that of the ninjas in this world. When he reaches a certain level of strength, he may encounter a bottleneck that he cannot overcome.

"This soul transformation has at least solidified my foundation a little bit... But I can't worry about that now. At least when I encounter a bottleneck, my strength will definitely be much stronger than that of the Otsutsuki clan."

(End of this chapter)