After entering the wooden house, Sato opened his backpack but did not retrieve the storage scrolls containing the body tissues of Uzumaki Kushina and Uzumaki Mito. Nor did he open the storage scrolls obtained from Orochimaru, which held the bodies of the previous Hokages.
Impure World Reincarnation, aside from requiring body tissue or cells as a medium for summoning, also necessitated a complete corpse as a vessel or a living person as a sacrifice to successfully summon the soul of the medium. However, Sato had already consumed the bodies of Uzumaki Kushina and Uzumaki Mito, leaving only fragments of their remains. To release them from Impure World Reincarnation, Sato needed to capture two living individuals as sacrifices.
In the case of previous Hokages summoned through Impure World Reincarnation, in addition to human sacrifices, Shinigami masks were also necessary to release their souls from the Shinigami's stomach.
For now, Sato had no intention of performing this ritual, whether for the reincarnated Kushina and Mito or for the Hokages. The former held no significance in his transformation into a perfect being.
The key to Sato's transformation lay in obtaining the corpse of an Uchiha clan member with awakened sharingans. Sato's pursuit was the Susanoo, which he had set as one of his goals before the Fourth Ninja World War. With a physique second only to Ōtsutsuki Ashura, Sato desired the Eyes second only to Ōtsutsuki Indra—the Mangekyō Sharingan.
Moreover, as a celestial being, once Sato unlocked the Eternal Mangekyō Sharingan, he would be immune to the drawbacks of the Mangekyō Sharingan, such as blindness. Therefore, once his Three Tomoe Sharingan evolved into the Mangekyō Sharingan, Sato's strength would experience a tremendous surge.
"Untie," Sato commanded.
He retrieved a storage scroll from his backpack and extracted the large box it held. Dumping all the other storage scrolls onto the ground, he unwrapped one of them, revealing a coffin. Opening the coffin, Sato discovered an embalmed corpse dressed in black attire adorned with the Uchiha family crest.
Taking the corpse out of the coffin, Sato recalled the information he had obtained from Orochimaru regarding Impure World Reincarnation. Instead of immediately sealing the soul, he first created several Wood Style Kunai and inscribed a spell on them using chakra, similar to the Flying Thunder God technique. Squatting down, he formed hand seals and slammed his hands on the ground.
"Reanimation Jutsu!" Sato exclaimed.
As his palm touched the ground, chakra surged out like a sealing technique, transforming into black rune-shaped tadpoles that spread toward the corpse, resembling snakes. When the runes reached the corpse, a wooden floor suddenly turned into a cloud of white dust, magnetically drawn to cover the body and transform it into a white mummy.
Subsequently, the mummy reverted back into the Uchiha corpse, but with some notable differences. Unlike the previously well-preserved corpse, the fatal wounds had disappeared, and the body had cracks, signifying its status as an Impure World Reincarnation.
Simultaneously, the soul of the deceased, who had been in the afterlife for several years, returned to its reanimated body. Aside from the cracks and absence of pain, it was indistinguishable from true resurrection.
"Rise," Sato commanded
.
The Impure World Reincarnation succeeded, and Sato controlled the reanimated corpse, causing it to stand. Sato then took a wooden kunai inscribed with the same spell and thrust it into the corpse's head.
A miraculous scene unfolded as the wooden kunai, surrounded by rippling waves, seemingly entered a different space rather than piercing the corpse's head. At that moment, Sato gained absolute control over the corpse.
Raising his index finger, Sato caused the Uchiha corpse to open its eyes. The hollow eye sockets were filled with black orbs, which quickly transformed into Three Tomoe Sharingan under Sato's command.
"Oh? It's Three Tomoe Sharingan," Sato remarked in surprise. "The first one is the Three Tomoe Sharingan,. It seems my luck is pretty good."
Sato extended his hand, gripping the reanimated Uchiha's neck, and used the "Hand of Devouring" to absorb it into the refining space.
The scene shifted to the mysterious bead's refining space. The Impure World Reincarnation body, possessing an immortal nature, was no different from other corpses and living individuals in the space. It transformed into countless molecules under the influence of the supreme power of rules.
However, when Sato sensed the refined energy from the Impure World Reincarnation body, he regretfully murmured to himself, "It seems that 'infinite Chakra' does not refer to an immense amount of Chakra. Instead, it implies Chakra that replenishes itself infinitely."
Impure World Reincarnation had two crucial attributes: an immortal body that could be resurrected as long as the soul remained intact and an inexhaustible amount of Chakra.
Sato had devoured the Impure World Reincarnation body, expecting to acquire limitless Chakra. However, it became apparent that this was not the case. Nevertheless, Sato had obtained what he desired.
As he had surmised, when an Uchiha clan member died, their soul would take Chakra and Life Force with them. After the refining energy was expelled by the mysterious bead, Sato felt his Yin Release Chakra and Sharingan abilities increase significantly.
Furthermore...
As Sato's physical prowess grew, the upper limit of energy he could bear exceeded. Previously, the warm current that engulfed Shisui could last for a week in Sato's child's body. Now, he could absorb the refined energy of an Elite Jōnin or even a Kage-level powerhouse within half a day.
Feeling the surge in his Sharingan power, Sato's fighting spirit soared. He continued to extract the remaining Uchiha corpses, freeing them from Impure World Reincarnation, and controlling them to activate their Sharingan for him to devour.
Although there were only 137 Uchiha corpses in the secret room of the Hokage building, representing a portion of the Uchiha clan's genocide, with the remaining bodies in possession of Uchiha Obito, there were still over 70 corpses left.
All of these corpses were Uchiha who had awakened their Sharingan during their lives. If Sato harvested their Sharingan and stored them, it would fill a wall just like Uchiha Obito's collection.
Among them, 20 corpses possessed Three Tomoe Sharingan, while the rest possessed the Two Tomoe Sharingan; none had the Single Tomoe Sharingan.
Evidently, Shimura Danzō was quite selective and did not settle for anything less. His discerning taste turned out to be advantageous for Sato.
After devouring the twenty-fifth corpse, Sato felt a faint coolness in his Three Tomoe Sharingan. This cool sensation turned into a tingling after devouring the fiftieth corpse.
By the time Sato devoured the sixty-seventh corpse, an auditory hallucination seemed to echo in his ears.
BOOM!
Like a collapsing dam, an endless surge of Yin Release Chakra burst forth from Sato's brain, connecting with his eyes. Simultaneously, the mysterious bead within Sato's soul emitted a dazzling black light.
The light transformed into an energy beam that traversed from Sato's soul to his body, merging with the Yin Release Chakra. This fusion birthed a mysterious and unknown ability.
As this new ability manifested in his eyes, the Three Tomoe Sharingan in Sato's eyes disappeared, replaced by a blooming black lotus pattern.
This is incredible... Mangekyō Sharingan!
The start of this chapter made no sense, had to delete like 8 sentences.