Obito had originally planned to launch a silent surprise attack, killing Naruto or Sasuke first to eliminate the two greatest wild cards of the future.
But after watching for several days, he still had not made his move.
Either Kakashi stayed by Naruto's side the entire time, making him unwilling to show himself;
Or Uchiha Itachi guarded Sasuke, and against Itachi, he had no confidence.
With so many obstacles in his way, Obito could only abandon his surprise attack for now, hide in the shadows, and review his entire plan, adjusting the pace of his moves.
Black Zetsu, meanwhile, was being even more cautious and keeping an even lower profile than Obito.
When he saw the Eye of the Moon Plan fail on the Sky Screen, he had no time for anger or resentment.
Beyond the plan's failure, he had caught a detail that alarmed him far more-Sasuke Uchiha awakening the Rinnegan.
Black Zetsu's heart filled with wariness.
He knew there was only one reason Sasuke could awaken it in his teens.
"Hagoromo, Hagoromo."
"After all these years, you really never stopped watching this Shinobi World."
"Sasuke's Rinnegan was your doing, wasn't it?"
But no matter how hard Black Zetsu thought, he could not make sense of it.
He had schemed for a thousand years, manipulating the history of the Shinobi World and laying the groundwork, step by step, for Kaguya's resurrection.
He was certain that Hagoromo, the Sage of Six Paths, knew every part of his scheme and all his intentions.
Yet through all those years, Hagoromo had watched coldly from the sidelines, never once intervening or taking any action.
For the first time, Black Zetsu found himself facing a situation he could not understand.
"What exactly are you trying to do?"
"You keep watching the Shinobi World, yet