In some fanfictions, Naruto might go back in time and try to save his parents. He could alter the events that led to their deaths. This would not only change his own life but also have a huge impact on the entire ninja world as his parents were very powerful ninja.
One interesting plotline could be Snape going back in time and trying to prevent the death of Lily Potter. He might use his knowledge of the future to change certain events that led to her demise. Another could be him attempting to correct his own past mistakes, like his relationship with James Potter. Maybe he goes back and tries to befriend James earlier to avoid all the enmity that grew between them over the years.
One interesting plotline could be Harry going back in time to prevent certain deaths, like Sirius Black's. He might use his knowledge of future events to change the course of history and save his loved ones.
One interesting plotline could be Naruto using his knowledge of the future to prevent certain tragedies that occurred during the war. For example, he might be able to save some of the fallen comrades. Another could be his attempts to change the political situation in the ninja world for the better, leveraging his experiences.
One interesting plotline could be Naruto using his future knowledge to prevent the Uchiha massacre. He might be able to change things in a way that doesn't lead to Sasuke's downward spiral. Another could be him training his younger self to be stronger faster, so that he can face the early threats in the Naruto world more effectively.
One interesting plotline could be Naruto using his future knowledge to prevent certain tragedies. For example, he might stop the Uchiha massacre by warning the clan or finding a way to resolve the conflict between them and the village earlier. Another could be him training his younger self more effectively, leading to a much stronger Naruto at an earlier age. He could also change the way he interacts with characters like Sasuke, maybe preventing Sasuke from leaving the village in the first place.
One interesting plotline could be Naruto using his future knowledge to prevent certain tragedies. For example, he might stop the death of his parents. He could also use his knowledge of jutsu to quickly become a much stronger ninja at a younger age and change the power dynamics in the village.
One idea could be Naruto going back in time and preventing the Uchiha massacre. He could use his knowledge of future events to stop Itachi from having to make that tragic choice.
One interesting plotline could be Naruto encountering different versions of his friends in various universes. For example, he might meet a Sasuke who is a powerful mage instead of a ninja. Another could be Naruto facing new and unique villains that only exist in certain multiverse realms. He may also have to adapt to different ninja cultures and power systems in different universes, which would be really exciting to explore.
Another plotline could be Albus Severus trying to correct a mistake made by one of his ancestors. This might involve him interfering with a family feud or an old magical spell gone wrong. As he travels through time, he has to be careful not to disrupt the fabric of time too much, which adds an element of danger and suspense to the story.
One interesting plotline could be Naruto arriving in an alternate universe where the Akatsuki are the heroes. He has to figure out how to navigate this new world where his former enemies are now revered.