One possibility is that Naruto with his Rinnegan powers could disrupt the power balance in the Sannin era. His modern jutsu and knowledge might give him an edge. For example, he could use his Rasengan in ways that the shinobi of that time have never seen. He might also form unexpected alliances, like befriending Orochimaru before he goes bad, which could change the entire future of the Naruto world.
He could change the fates of the Sannin. For example, if Naruto helps Jiraiya in his battles, Jiraiya might not die later. This would have a huge impact on the overall Naruto story. Also, Naruto's Rinnegan abilities could make him a target for the villains of that era. They would either try to steal his power or kill him, which would create new storylines.
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 a Sasuke time travel to the Sannin era fanfiction, Sasuke would be faced with a lot of opportunities and challenges. He could use his knowledge from the future to his advantage. For example, he might know about certain threats that the Sannin were not aware of. He could also be a key player in the battles of that era. His Sharingan would be a very valuable asset. However, he would also have to adapt to the different political and social situations of that time. His interactions with the Sannin would not only change his own future but also the future of the shinobi world as a whole.
The Rinnegan can be used in time travel fanfiction in Naruto in various ways. It could be used to open portals to different time periods, kind of like how it can create spatial portals in the original series. For example, a character might use the Rinnegan to travel back to the era of the First Hokage to gain knowledge or power.
There's also 'Naruto's Time - Traveling Rinnegan Adventure'. This fanfiction focuses on Naruto exploring different time periods with his Rinnegan ability. He meets his predecessors and learns a great deal about the origin of the ninja arts. It's a great read for those who love to see Naruto in a more introspective and knowledge - seeking role as he travels through time.
Sasuke's abilities would be both advanced and out of place. His Sharingan skills would be very powerful compared to most in the Sannin era. But he would lack some of the basic knowledge and skills that were common in that time. For example, he might not be as well - versed in some of the traditional ninjutsu styles.
The Rinnegan's time travel can completely change character relationships. For example, if a character travels back in time, they might meet their friends or enemies at a different stage of their lives. In a harem fanfiction, this could mean that a male character meets a female character before she has certain prejudices or before she has fallen in love with someone else. So, the time travel allows for a fresh start in the relationship.
Definitely Hiruzen. He was not only their teacher but also the Hokage at the time. His interactions with the Sannin, whether it was giving them advice or reprimanding them, were crucial. Then there's Dan. His death had a profound impact on Tsunade. In addition, characters like Shikaku Nara or Inoichi Yamanaka could be interesting to include. They were important members of the Leaf village and could have had some interactions with the Sannin, even if they were not as prominent at that time. It would give a more complete picture of the village's ninja population during that era.
In 'Long Rinnegan Naruto Time Travel Fanfiction', a common plot is Naruto being sent back in time accidentally due to some malfunction of his Rinnegan power. Once in the past, he has to figure out how to get back while also trying to use his knowledge and power to make the world a better place. He might team up with younger versions of the legendary sannin or try to change the fate of some of the minor characters. It's always fascinating to read about how the time - traveling Naruto disrupts the normal flow of the Naruto world.