If Naruto got the Rinnegan, he might become more cautious. The power of the Rinnegan is so great that he would realize he needs to be more careful with it. He wouldn't be as brash as before.
A frequent theme is adaptation. When the Rinnegan is introduced into a crossover, characters have to adapt to this new power dynamic. For example, in a Naruto - Harry Potter crossover, the wizarding world has to adapt to the existence of the Rinnegan. Also, redemption can be a theme. A character who has misused the Rinnegan may seek redemption in the crossover story.
One possible plot could be that a character from Naruto with the Rinnegan somehow gets transported to the Inuyasha universe. Maybe they team up with Inuyasha and his friends to fight a common enemy. For example, the power of the Rinnegan could be used to counter some of the powerful demons in the Inuyasha world. The character might also introduce new jutsu or abilities to the Inuyasha gang, which could change the way they fight battles.
A main feature is often the overpowered nature of Naruto with the godlike Rinnegan. His abilities are enhanced to a level that allows him to do things like effortlessly defeat powerful opponents. Another feature can be the exploration of new jutsus or techniques that come with this form of the Rinnegan.
One popular 'godlike rinnegan naruto crossover fanfiction' might be 'Naruto: The Rinnegan God'. It combines the powerful concept of the Rinnegan in Naruto's world with a god - like twist. The story often delves into Naruto having enhanced powers due to a special form of the Rinnegan, leading to new and exciting adventures against powerful foes.
There's also 'Naruto and the Rinnegan Legacy'. This fanfic delves deep into the lore of the Rinnegan and how Naruto fits into it. It explores how Naruto uses the powers of the Rinnegan not just for fighting but also for unifying the ninja world. The character development in this fanfic is quite remarkable as Naruto has to adapt to this new power while still staying true to his original self.
The plot could involve Naruto with Rinnegan powers somehow ending up in the Pokemon world. Maybe he'd use his ninja skills to catch Pokemon in unique ways. For example, he could use his shadow clone jutsu to surround a wild Pokemon and then use a pokeball. He might also form alliances with certain Pokemon trainers who are intrigued by his strange powers.
Well, a cool plot for a Rinnegan Naruto crossover fanfiction could be that there is a rift between the Naruto world and a world where the Rinnegan is more common. Naruto gets pulled into this other world and has to adapt to the different power system there. He meets characters who have mastered the Rinnegan and has to learn from them to find his way back home. Along the way, he discovers a connection between the two worlds that was hidden for centuries.
Well, in this fanfiction, the story could start with Naruto being in a strange new world, which is the world of Fairy Tail. His Rinnegan gives him unique abilities that both shock and intrigue the Fairy Tail wizards. They initially view him with suspicion but as they see his skills in combat and his determination to help, they accept him. And together, they embark on a journey to stop an ancient evil that threatens both their worlds. The Rinnegan could allow Naruto to understand the magic in the Fairy Tail world in a way that no one else can, leading to some really interesting interactions and battles.
One possible antagonist could be a rogue ninja who also wants the power of the Rinnegan. He might see Naruto as a target to either steal the power from or eliminate so that he can be the most powerful in the ninja world. This character could be a new creation or an existing villain with a new motivation.