The Moon Eye Plan was not about creating a world where Rin could be brought back to life. It was about creating a world where war could never take her away.
If all Obito wanted was to revive Rin,
he could use Nagato's Rinnegan to perform the Reanimation Technique and bring her back.
There was also the Impure World Reincarnation Jutsu!
And the One's Own Life Reincarnation that Chiyo had used to revive Gaara.
Once Ninja reached a certain level, they discovered that bringing someone back to life was not all that difficult.
But reviving Rin was not what Obito wanted. To him, this world was filled with despair.
If you did not kill me, I would kill you.
If you killed my family, I would slaughter your entire village.
This was a world trapped in endless war.
Obito wanted to build a world of absolute peace. Rin would have liked a world like that.
After a single glance at the ruins of Rōran, Obito looked away.
He believed he was the Savior. He should not change another era.
Konan wanted to return to the past, to the time when Yahiko was still alive. She wanted to change the day Hanzō captured her and find a way to save Yahiko.
Liao Wu saw the longing in Konan's eyes and warned her, "Even if you go back and change what happened, it won't affect this era!"
"Do you know the grandfather paradox?"
Konan and the others nodded. They all knew of that logical contradiction in time-travel theory.
This world's scientific foundations were fairly solid. Biology had already defined cells, and there were techniques for cell fusion, cell transplantation, and human cloning.
As for technology, there were computers, surveillance devices, long-distance video transmission, and radio.
The grandfather paradox went like this: suppose