Some fanfics might have a plot where Naruto himself travels back in time. He could use his knowledge of the future to train harder, or he might try to save some of his friends who died in the original timeline. This could also result in some heartwarming moments as he reunites with characters from his past, like his parents, and has a chance to interact with them in a different way.
One interesting plot could be Naruto seeing how the village has developed in the future. He might be amazed at the advanced technology and new ninja techniques. For example, he could discover new ways of using chakra that he had never thought of before.
One interesting plot could be that Naruto and Sasuke travel back to their childhood days. They use their knowledge of the future to prevent certain tragedies, like the Uchiha massacre. They might also try to change how they first interacted, making their bond stronger from the start.
One interesting plot could be that Naruto and Yoshina time travel to the era of the Sage of Six Paths. They could learn about the origin of chakra directly from the source. Naruto might gain new powers or a deeper understanding of his own abilities. Yoshina could also have her own revelations. Another plot could be that they are sent back to when Naruto was a child and they have to prevent Orochimaru from infiltrating the village earlier. This would change the power dynamics in the village and Naruto's growth path.
Some great Naruto Shippuden fanfic concepts could be a story centered around the Akatsuki members before they joined the organization. What led them to their paths of darkness? Another could be a fanfic where Hinata becomes a super - powerful ninja in her own right, not just in relation to Naruto. She could have her own unique set of skills and missions. And then there could be a fanfic that focuses on the rivalry between Rock Lee and Neji during the Shippuden era, how they pushed each other to grow and the moments of friendship in between their competitive streaks.
One interesting plot could be Ben traveling back in time to meet his younger self and having to hide his identity while trying to prevent a future disaster that his younger self unknowingly causes.
One interesting plot could be Sarada traveling back to the time of the founding of Konoha. She might witness the great battles and negotiations that led to the creation of the village. This would give her a new perspective on the history and values of her home.
Kakashi can be a popular choice too. His intelligence and combat skills are valuable assets in any situation, including time - travel fanfics. He could be the one guiding other characters through the time - travel chaos, using his knowledge of the past and his strategic thinking to deal with the new challenges that come up.
A cool plot in Naruto Konoha 12 Time Travel Fanfiction might be that they go back to the time of the Nine - Tails attack on Konoha. They could work together to try and prevent the Nine - Tails from causing as much destruction. Maybe Sakura, with her medical skills, could save more lives. Shikamaru could come up with a better strategy to deal with the situation. And Naruto, well, he could try to communicate with the Nine - Tails in a different way since he has the experience of befriending it in the future. This would change the whole future of Konoha and how Naruto is perceived in the village.
One interesting plot could be Naruto and Naruko traveling back to the time when the Uchiha clan was about to be massacred. They could try to prevent it, which would change the whole future of the ninja world. Maybe they use their future knowledge and skills to stop Itachi from carrying out the order.
Well, in some fanfictions, Naruto and Tsunade time travel and end up changing the power dynamics in the ninja world. Maybe they help a small village become a major power by introducing modern ninja concepts. Also, they could time travel to a period when the Akatsuki was first formed and try to disband it before it causes too much chaos.