"You said my life had entered its final countdown? How laughable. I am the reincarnation of the Sage of Six Paths, possessing power akin to a god. How could a mortal's eye technique possibly work on me?"
Nagato naturally dismissed Black Zetsu's words as alarmist nonsense.
Whoosh! He immediately pointed the Six Paths Staff in his hand at Black Zetsu and said coldly, "And you must explain this clearly to me. What is this incarnation of the Divine Tree? What about your mother, Ōtsutsuki Kaguya? Just how much have you hidden from me?"
"Since things have come to this, I'll tell you about my mother, the progenitor of Chakra, Ōtsutsuki Kaguya..."
Black Zetsu had also been struck by Ayakashi, leaving him with only three days to live. Realizing this, he lost his patience and resolved to race against time during his final three days, reviving Kaguya at any cost. Thus, he laid everything bare before Nagato!
Of course... there was one thing Black Zetsu would never tell Nagato: Kaguya would replace him.
After hearing Black Zetsu's account, Nagato asked, "The Sage of Six Paths was Kaguya's child? You are also Kaguya's child, so... you are the Sage of Six Paths' younger brother?"
Black Zetsu said, "Though I do not wish to admit it and consider it shameful, ethically speaking, I am indeed the Sage of Six Paths' younger brother!"
"Ha ha ha ha ha ha ha..." Nagato actually burst into laughter. When he finished, he said coldly, "Even the Sage of Six Paths could not escape the passage of time. How could you possibly have lived until now? What you're saying is complete nonsense!"
Nagato considered himself the Sage of Six Paths' reincarnation, and the Sage of Six Paths held an unshakable place in his heart. He believed that if