Flaw in Impure World Reincarnation

Orochimaru's base in the Land of Rice Fields was probably his largest. It had several underground floors, complete with laboratories, prisons, and warehouses. Several training grounds were also built on the ground, and towering walls were erected using advanced Earth Release. A large-scale Barrier Ninjutsu enveloped the entire base.

Many people live here. Although Kato Osamu has not met them all, he knows a little about them. All sorts of strange Kekkei Genkai holders provide Orochimaru with a constant stream of experimental 'materials'.

"The Impure World Reincarnation has flaws... Orochimaru- sensei..."

In the training ground on the ground, Kato Osamu looked at the several coffins erected on the ground, and unrolled the scroll in his hand. Long ago, when he was still in Konoha, Kato Osamu had already come into contact with the Impure World Reincarnation Jutsu through Orochimaru, but this was the first time he had studied it in such detail.

However, because of this, with his current mastery of Soul Secret Technique, he did not spend much effort to discover some flaws in this alternative Reincarnation Technique born from Tobirama Senju.

The Second Hokage Tobirama Senju Water Release, followed by various Ninjutsu targeting the Uchiha Clan. However, his research into Soul Secret Technique was probably far inferior to that of Kato Osamu at present.

"Oh?" Orochimaru, who was already plotting a certain plan in his mind, remained expressionless, but his eyes narrowed as he quietly looked at Kato Osamu.

"The Impure World Reincarnation can summon the soul of the dead from the Pure Land. The summoner uses specific Cursed Seal and runes to control the Impure World Reincarnation body to fight for them..."

"Although the Impure World Reincarnation body is limited by the sacrifice and the caster and cannot unleash the full power of the deceased in life, its special body allows it to continuously regenerate after being injured. As long as the summoner's contract exists, it can be considered a machine capable of eternal battle..."

"The development of this secret technique is a truly imaginative and awe-inspiring concept..."

Kato Osamu gently shook the scroll in his hand and slowly walked towards the several upright coffins in the training ground. He placed one hand on them, feeling the Chakra energy contained within.

"But, Orochimaru- sensei, have you ever considered the possibility that an Impure World Reincarnation dead person might also possess the secrets of the Impure World Reincarnation Jutsu, and even be able to forcibly break the contract with the summoner...?"

"So, this immortal body that can constantly regenerate, the near-limitless Chakra, and the completely uncontrollable soul of the dead..."

"This is probably something no one wants to see..."

His voice wasn't loud, but it made Orochimaru's brows furrow more and more, as if he was constantly calculating the possibilities in his mind. He remained silent for a while before slowly speaking.

"You mean, this is a hidden plan that Tobirama Senju deliberately concealed..." Orochimaru's eyes flashed with a sharp light. He had no doubt about Kato Osamu's mastery of Soul Secret Technique. As far as he knew, it was not impossible for Tobirama Senju to do such a thing. He was not a straightforward person like his brother.

"Perhaps, or perhaps he simply didn't consider that possibility..." Kato Osamu tossed the scroll to Orochimaru, remaining noncommittal. He wasn't particularly interested in the Impure World Reincarnation Jutsu or the method of commanding the dead in battle, but he was somewhat curious about the method of summoning the dead from the Pure Land.

"Or, we could have him explain it to us himself..."

Orochimaru glanced at Kato Osamu, a hint of amusement in his eyes, seemingly eager to try.

"It's up to you. It's not impossible, but I hope Orochimaru- sensei can be confident in subduing Tobirama Senju, who possesses unlimited Chakra and an immortal body..." Hearing this, Kato Osamu smiled, turned, and left. He had already told Orochimaru about the Impure World Reincarnation technique; as for how to proceed, that was naturally Orochimaru's own decision...

"Osamu will have a chance to meet him..." Orochimaru chuckled as he watched Kato Osamu's retreating figure, but his brows furrowed slightly as he seemed to be pondering a solution to the problem.

Orochimaru believed Kato Osamu's words. He had his own judgment; he just hadn't considered this possibility before. But now that he knew, a little research would make it clear.

However, improving Ninjutsu like the Impure World Reincarnation is not something that can be accomplished in a short time...

"Pure Land..."

"I see..."

Back in the laboratory, Kato Osamu had a general understanding of how to establish a connection with the spirits in the Pure Land during the Impure World Reincarnation.

Impure World Reincarnation, which uses the soul of a sacrifice to exchange for the soul of another deceased person to return to the mortal world, is essentially a deal with the guardian of the Pure Land, perhaps the 'Shinigami'.

The moment the soul of the sacrifice goes to the Pure Land is the moment the passage between the Pure Land and reality is opened. Through a certain message on a specific rune, using the deceased's flesh and blood as an anchor point, the target soul can be called back from the Pure Land.

Therefore, the Second Hokage Tobirama Senju, should not be underestimated. Such a secret technique is not something an ordinary person could develop. It involves not only Soul Secret Technique, Yin-Yang Release Technique, summoning techniques, Sealing Jutsu, but also life and death, as well as some kind of contract with the 'Shinigami'.

"The Dead Demon Consuming Seal..."

"Impure World Reincarnation..."

"Senju Clan and Uzumaki Clan seem to possess the potential to communicate with Shinigami (death gods)..."

Now that the Shinigami Mask from the Uzumaki Shrine has been retrieved, and Kushina Uzumaki has taught Orochimaru and Kato Osamu a secret technique for the Uzumaki Clan to communicate with the Shinigami, he has begun preparations to summon the First and Second Shinigami...

These people, who are far removed from this era and once stood at the pinnacle of an era, must know some truths that ordinary people in this world do not understand.

As Kato Osamu studied the secret scroll he had obtained from Kushina Uzumaki, he noticed some similarities between it and the Impure World Reincarnation technique, and began to have some guesses.

Having thoroughly understood the principles of the entire secret technique, Kato Osamu couldn't help but think of the scroll he once possessed, and a hint of surprise flashed in his eyes.

"If the ancestors of the Senju, Uzumaki, Uchiha Clan, and Hyuga clans were all the same person, is it possible that this ancestor actually made some kind of 'Summoning Contract' with the 'Shinigami'...?"

Sitting quietly in the laboratory, Kato Osamu looked around, his gaze involuntarily falling on the several clones he was cultivating. A bold idea suddenly popped into his mind, and he couldn't suppress it any longer...

"The Pure Land... I want to go to the Pure Land!"