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.
Perhaps a plotline where Naruto travels to a universe where the Akatsuki are the heroes. He has to deal with the shock of seeing his former enemies as the good guys. He might also befriend some of them and learn about their motives and how this different world made them into heroes. This would lead to a lot of character development for Naruto as he questions his own views on good and evil.
One interesting plotline could be the OC encountering different versions of themselves in various universes. It might lead to self - discovery and growth as they compare and contrast their lives.
One interesting plotline could be Izuku encountering different versions of himself in various universes. Maybe in one universe he's a villain, which would be a huge shock to the original Izuku and lead to a great deal of self - reflection.
Well, in some 'Harry Potter travels the multiverse fanfiction', there could be a plotline where Harry discovers a universe where he was never born. This would force him to re - evaluate his own importance and the role he plays in the grand scheme of things. Maybe he has to figure out how to bring magic back to that universe or deal with the consequences of his non - existence. Another cool plotline might be that he travels to a universe where the wizarding world is at war with a race of powerful magical creatures he's never encountered before, and he has to broker peace.
A great plotline would be Naruto's journey to a universe where all the tailed beasts are evil. With his godlike abilities, he tries to understand why they are this way and attempts to change them for the better. He might also face opposition from the inhabitants of that universe who believe the tailed beasts should be left alone or destroyed. This would create a complex moral and physical battle for Naruto.
One interesting plotline could be Naruto making unexpected alliances with different clans in the elemental nations. For example, he might team up with a water - based clan and learn their unique water - style jutsu techniques, which he can then combine with his own skills.
One possible plotline could be Naruto arriving in a universe where chakra doesn't exist, and he has to learn new forms of power. Another could be that he meets alternate versions of his friends with different personalities. For example, Sasuke could be a pacifist in that universe.
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 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 concept is seeing different versions of Naruto characters in alternate universes. For example, a Naruto who becomes a villain instead of a hero. Another concept could be the different power levels and abilities the characters possess in these multiverse settings. Also, the relationships between characters might be completely different, like Sasuke and Naruto being enemies from the start in one universe.
One interesting concept is alternate versions of characters. For example, a Naruto who became evil due to different life experiences in the multiverse. It allows for exploring different character arcs.