Karot ignored the two of them and continued.
"Kaguya Otsutsuki's plot was discovered by the Three Great Sage Regions. The Toad Sage of the Three Great Sage Regions beguiled the Sage of Six Paths and his younger brother into sealing their mother inside the moon in the sky. While Otsutsuki was being sealed, she gave birth to a third son."
"This third child drove a wedge between the Sage of Six Paths and his sons, turning them against each other and causing the Sage's two sons to struggle endlessly through reincarnation. Hashirama Senju and Madara Uchiha were the reincarnations of the Sage of Six Paths' sons."
"T-this..."
Shisui and Orochimaru were both stunned.
"The reason the First Hokage and Madara Uchiha were so powerful was that the Sage of Six Paths' sons were reincarnated with their Chakra."
"No wonder."
Orochimaru suddenly understood. No one in the Ninja World had ever reached the First Hokage's level since. So that was why.
"And Madara was deceived by Black Zetsu—the third son of Kaguya Otsutsuki—and turned against the First Hokage, setting another cycle of reincarnation in motion."
"But why did Black Zetsu do that? If it was just to avenge his mother, the Sage of Six Paths is already dead."
Shisui asked, deeply confused.
"Black Zetsu wanted to save his mother. And who said the Sage of Six Paths was dead?"
Karot dropped another bombshell.
"What?!"
This time, even Orochimaru cried out, not just Shisui.
"Did you two think I built an energy barrier for no reason? It's to keep the Sage of Six Paths out. He's been living in the Ninja World all this time in the form of a spirit."
The bombshell left Orochimaru and Shisui looking stricken. A figure from legend had been watching the Ninja World's development all along.