Well, in 'naruto inside out fanfiction', we could see unique interpretations of the characters' memories. For example, Sasuke's memories of his family and the Uchiha clan's downfall could be explored in a new light, showing how these memories shape his actions and emotions. Also, the concept of different 'islands' in the mind, like an 'island of jutsu training' for Naruto, could be really fascinating.
One interesting concept could be exploring different emotions for the characters other than the main ones shown in the movie. For example, what if there was a secondary emotion that was a mix of sadness and joy that Riley had to deal with.
One idea could be creating an OC who is a new emotion in Riley's mind. For example, an emotion of 'Wonder' that gets activated whenever Riley experiences something truly amazing. This OC could interact with the existing emotions, like Joy being both excited and a bit jealous of this new emotion's unique role.
Some fanfictions might explore the idea of Naruto befriending an Espada. This friendship could lead to Naruto learning about different ways of combat and power management from the Espada. It could also result in the Espada having a change of heart due to Naruto's positive influence, and together they could face new threats in the Naruto universe that neither could face alone.
In Naruto fanfiction, the Sharingan is often explored in unique ways. For example, some fanfictions might expand on its ability to not only copy jutsu but also to predict an opponent's moves on a whole new level. Another interesting bloodline concept could be the Uzumaki's massive chakra reserves, and fanfictions may play with how this could be used in different scenarios, like creating entirely new jutsu.
In 'naruto dark naruto fanfiction', the concept of Naruto's doppelganger or 'dark Naruto' is often explored. This could be a manifestation of his repressed negative emotions. It might be that this dark Naruto has its own goals that are contrary to the real Naruto's. For instance, it could want to destroy the Hidden Leaf Village instead of protecting it. And the story could revolve around how Naruto deals with this inner darkness, either by trying to suppress it or, in a more extreme version, merging with it and becoming a different kind of hero or anti - hero.
One interesting concept could be an exploration of Naruto's dark side. It might show how his experiences could have turned him truly evil, like if he had been more influenced by the hatred in the ninja world from the start. Maybe in this fanfiction, he uses his powers for self - gain rather than for the good of the village.
A possible plot is that the control panel in Riley's mind gets a malfunction, and the emotions have to work together in a completely new way. They might have to swap their usual functions, so Sadness has to take on the role of Joy for a while. This could lead to some really strange behaviors from Riley on the outside. Also, what if an outside force, like a dream character, tries to invade the inside world of Riley's emotions and disrupt their harmony?
One interesting concept could be a crossover of Naruto's ninja skills with Jenova's unique abilities. For example, Naruto's clones might interact in strange ways with Jenova's regenerative powers. Another concept could be the characters from Naruto having to face the threat of Jenova in their world, leading to new alliances and strategies.
One interesting concept could be the exploration of new and unique bloodline abilities that are not in the original Naruto series. For example, a fanfiction might introduce a bloodline that allows the user to control time on a small scale. Another concept could be the combination of different existing bloodlines to create a hybrid with extraordinary powers. Some fanfictions also delve into the origin and history of the known bloodlines, providing a deeper backstory that was not fully explored in the original.
In dimesional naruto fanfiction, there might be the idea of Naruto or other characters traveling between dimensions. This could lead to some really cool scenarios. For instance, Naruto ending up in a dimension where the Akatsuki are the good guys, and he has to figure out how to deal with that. It could also involve different versions of known characters in other dimensions, like a female version of Sasuke with her own unique backstory and abilities.