Another aspect in such fanfictions could be the origin of the Kyuubi seal. Some writers might delve into ancient ninja secrets and forgotten jutsu that were used to create the seal in the first place. They might also explore if there were other possible ways to seal the Kyuubi that were considered but not used. This can add a whole new layer of mystery and intrigue to the Naruto universe.
One possible fanfiction could involve Naruto learning a new technique that accidentally weakens the Kyuubi's seal, leading to a partial release of its power. This could put the Hidden Leaf Village in danger as Naruto struggles to regain control.
Some fanfictions focus on the idea of a different kind of seal being used on the Kyuubi. Maybe a more humane or symbiotic seal that allows Naruto to fully utilize the Kyuubi's power without the negative side effects. This can lead to a whole new Naruto, one who is more in control and perhaps even more powerful than in the original story.
The release of the Kyuubi could also attract other threats. Enemies from other villages or dark forces might see this as an opportunity to either steal the Kyuubi's power or take advantage of the chaos in the Hidden Leaf. Naruto, while dealing with the Kyuubi's power, would also have to face these external threats. His journey could involve learning to master the Kyuubi's power in a way that protects the village instead of endangering it.
Perhaps the Fem Kyuubi sees potential in Naruto that can only be fully realized once the seal is removed. She may believe that the seal is holding Naruto back from reaching his true strength. And she wants to see Naruto reach his full potential not just for his sake, but also because she has developed a sort of attachment to him during their time together while still being sealed.
Well, it might also lead to Naruto having a hard time controlling the power. Since the seal was there for a reason, to regulate the flow of the Kyuubi's chakra. Without the seal, he could go on a power - berserk, causing harm to his friends and allies accidentally. Just like when he first tapped into the Kyuubi's power as a kid, he wasn't fully in control and it was a dangerous situation.
Yes, in some fanfictions, Naruto is often depicted as the Kyuubi or having a very close connection to it. This can lead to really interesting and unique storylines that deviate from the original plot.
One common plotline is the Kyuubi teaching Naruto new and powerful jutsu. Since the Kyuubi has a vast amount of chakra and knowledge, it could share unique techniques with Naruto that are not part of the regular ninja training. Another plotline could be the Kyuubi's influence on Naruto's relationships. For example, some fanfictions explore how Naruto's connection with the Kyuubi affects how his friends and villagers perceive him. It can also lead to some interesting character development as Naruto has to learn to control the Kyuubi's power without being consumed by it.
In many Naruto fanfictions, Naruto might have developed some new and unique abilities that the Kyuubi has no defense against. This could make the Kyuubi, which is used to being a dominant and feared force, feel vulnerable. For example, if Naruto has the power to nullify the Kyuubi's chakra or to manipulate it in a way that goes against the Kyuubi's will, it would be a cause for fear.
The Karma Seal can change Naruto's appearance. In some fanfictions, it might give him a more menacing look with strange markings spreading across his body.