Naruto's countless cycles could roughly be divided into four stages.
The first stage was confusion, novelty, and doubt.
He was confused about why he had entered the cycle, fascinated by everything returning to how it had been five years ago, and then questioned whether it was Genjutsu.
The second stage was indulgence.
Relying on the experience accumulated through the cycles, he briefly defeated powerful enemies he had once been unable to reach, saved everyone he could save, and even became Hokage. Yet the thrill of every victory and every act of rebuilding came to an end in Konoha's sixty-eighth year.
All achievements and changes were nothing but fleeting fragments of a dream.
The third stage was systematic exploration and study.
With unlimited time, he systematically learned every piece of knowledge he could find—Ninjutsu, Forbidden Jutsu, Genjutsu, Taijutsu, all research materials belonging to individuals or ninja villages. He gathered the nine tailed beasts, became the new Ten-Tails Jinchuriki, even cast Infinite Tsukuyomi himself, and so on.
He also began deliberately engaging different people in deep conversations to extract information.
He tried to find a way to break the cycle through history, legends, and even the words of his enemies.
The fourth stage was the despair that came after every possible method had failed.
It was during the third stage that Naruto used his control over the Dragon Vein's power to travel through time to different eras, though it seemed he could only travel into the past.
Once he did something significant enough to alter history—such as killing or saving a relatively important person—and caused history to be completely rewritten, the cycle would begin.
However, this did not affect Naruto's earlier explorations and actions. Minor changes would not trigger the cycle.
Uchiha Hikari was someone Naruto discovered during the third stage.
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