Well, a cool plot might be Naruto ending up in a steampunk - style alternate universe. He'd have to adapt to the new technology while still using his ninja skills. Or perhaps he travels to a universe where everyone has a unique Kekkei Genkai, and his own abilities are considered weak. This would force him to find new ways to grow stronger. Also, he could land in a universe where the Fourth Great Ninja War never happened, and he has to decide if he should prevent it from happening in this new world or not.
One interesting plot could be Naruto arriving in a universe where the Akatsuki are the heroes. He'd be so confused as he's always seen them as villains. Another could be a universe where ninjas don't exist, but he still has his powers. He'd have to figure out how to hide or use them in a completely different world. Maybe in a third plot, he travels to a universe where all his friends are his enemies, which would be a huge emotional and physical struggle for him.
A great plot idea is Naruto traveling to an alternate universe where the tailed beasts are worshiped as gods. Naruto, being a jinchuriki, would be in a very strange position. He might be seen as a special envoy or something. Another plot could be that he enters a universe where there is a different system of chakra control. He'd have to learn this new system quickly if he wants to survive. Also, an interesting scenario would be if he travels to a universe where his parents are alive, and he has to deal with a completely different family dynamic.
Well, in some 'naruto goes to alternate universe fanfiction' plots, Naruto might find himself in a world where all the ninja clans have merged into one big super - clan. He'd have to navigate the complex politics within this new structure. Also, there could be a plot where he enters an alternate universe where the Fourth Great Ninja War never happened, but there are new threats emerging that he has to face. And then there's the idea of a universe where Naruto's parents are alive, and he has to deal with a completely different family dynamic.
One interesting concept could be a Naruto AU where the ninja world is a modern, high - tech society. Instead of using traditional ninja tools, they use advanced weapons and gadgets. Another could be an AU where the main characters have different elemental affinities than in the original story, which would change their combat styles and relationships.
One interesting plot could be that in the alternate universe, Harry is sorted into Slytherin instead of Gryffindor. This would completely change his relationships and how he approaches magic. Another plot might be that Voldemort never became evil in this alternate universe, and they end up as allies. There could also be a plot where magic works completely differently, like spells are cast by thoughts alone rather than incantations.
One interesting plot could be that Harry Potter is sent to an alternate universe where magic is used in a completely different way. For example, instead of using wands, they use hand gestures. Another plot might be that in the alternate universe, Voldemort won in the original world, and Harry has to find a way to reverse that in this new universe. Maybe in this alternate world, the Hogwarts houses have different characteristics and he has to adapt to that new social structure as well.
In Naruko fanfiction, one interesting concept could be a world where Naruko has a different set of ninja skills. For example, she might master a unique form of water jutsu that no one in the original Naruto universe has seen before. Another concept could be her relationships being completely different. Maybe she forms a strong bond with characters who were antagonists in the original story, like Orochimaru, but in this alternate universe, he has a different, more positive role to play. Also, the idea of Naruko leading a different ninja team with members from different villages could make for an exciting plot.
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.
If Naruto travels to an alternate universe, his relationships would change drastically. For example, if he meets his friends' alternate versions, they might have different personalities. His relationship with Sasuke could be very different. Maybe in this new universe, Sasuke is a laid - back person instead of brooding. His bond with Sakura could also change. If she's a more confident and powerful ninja in the alternate universe, Naruto might see her in a new light.
First, come up with a unique concept for your alternate universe. It could be something like a world where ninjas use modern technology. Then, think about how the characters will be different. For Naruto, maybe he's not an orphan or he has different abilities. Next, plan out the plot. You can start with a small change in the Naruto universe and build on it. For instance, if the Uchiha clan was never massacred, how would that change the relationships and the overall story?
In the 'naruto juubi alternate universe fanfiction', it would be interesting if the characters' relationships were reversed. Like Sasuke could be the one trying to protect Naruto who has the Juubi's power, because he realizes that Naruto's power is the key to a new world order that could benefit all ninjas.
One idea could be that Naruto finds himself in a universe where the Akatsuki are the heroes. He has to figure out how to co - exist or even join them to get back to his own universe. Another plot could be Naruto entering a universe where everyone has a different elemental chakra, like some have sound - based chakra instead of the usual five. A third idea is that he hops into a universe where the shinobi world is a utopia, but there are hidden secrets that are threatening to destroy this perfect world and he has to help.