One common theme is redemption. The Nanadaime Naruto often goes back in time to correct past mistakes or save characters who died. For example, he might try to save his sensei, Jiraiya.
One popular 'naruto nanadaime time travel fanfiction' is 'Naruto: Back to the Beginning' where Naruto travels back in time and uses his knowledge to change things. It has an interesting take on how his future skills impact the past.
One idea could be the Nanadaime Hokage (Seventh Hokage Naruto) traveling back in time to his younger self's era. He could use his knowledge of future events to prevent certain tragedies, like the death of some of his comrades. Maybe he could change the way he approached his training, leading to even greater power earlier on.
His relationship with his teachers would also change. For example, with Iruka - sensei, Naruto could show his gratitude in a more profound way. He could also use his skills as the Seventh Hokage to help Iruka in ways he couldn't before. And with Kakashi - sensei, Naruto could offer insights into future threats and how to better train the next generation, strengthening their bond as teacher and student even more.
Another idea is that Naruto in his role as the Seventh Hokage is transported to a world where ninjas are extinct, but there are other super - powered beings. He has to find a way to prove the value of the ninja way and also learn from these new beings to bring back what he has learned to his own world.
Well, when it comes to Naruto time travel and Rinnegan in fanfics, it's often about exploring new storylines. Maybe Naruto himself gets the Rinnegan and travels back in time to train his younger self. This would make him a much more powerful ninja at an earlier stage and could completely change the power balance in the Hidden Leaf Village and among the other ninja villages as well.
In many Naruto yaoi time travel fanfictions, it can be triggered by a powerful jutsu. For example, a secret time - space ninjutsu might go wrong and send a character back in time.
In a Naruto time - travel Minato fanfiction, Minato could be sent to the future. There, he would see how the village has changed, and might be shocked to find out about the Akatsuki and their actions. He could then work with Naruto and the others to fight against the Akatsuki using his unique skills and knowledge of the past. For example, he could teach Naruto some new jutsu that was lost over time.
A Naruto and Tsunade time travel fanfiction can be really interesting. It could involve them going back in time to change certain events in the Naruto universe. Maybe they go back to prevent a great tragedy or to save a beloved character. For example, they might travel back to the time of the Uchiha massacre and try to stop it, which would completely change the course of the story.
One great long Naruto time travel fanfiction is 'A New Path'. In this story, Naruto is sent back in time and uses his future knowledge to change many things in the Hidden Leaf. It has really interesting character development and a great plot that keeps you hooked from start to finish.