One interesting storyline could be about a new and powerful shinobi emerging during the Shinobi Wars and how they interact with Naruto and his friends. This new character might have unique abilities that change the dynamics of the battles.
There could be some original characters created specifically for the fanfic. For example, a young shinobi from a small village who has a unique power related to nature. This character could have a significant role in the Shinobi Wars, perhaps by forming an unexpected alliance with Naruto and his group. Their journey together, with the new character learning from Naruto and growing, would make them a memorable part of the fanfic.
One idea could be a story where a new, unknown shinobi emerges during the wars with a unique power that changes the balance of power. This shinobi could initially be seen as an enemy but later turn out to be an ally with a noble cause.
An older, retired shinobi who is forced to come out of retirement during the shinobi wars. He has old - fashioned techniques but a wealth of experience. He could mentor a group of young shinobi and help them develop new strategies based on his years of combat knowledge.
Naruto himself could be a main character, using his skills and influence to try and stop the clan wars. Another could be a young shinobi from a minor clan who has a special ability and wants to prove their clan's worth. And Sasuke could also be involved, perhaps having his own motives related to the clans.
One plot idea could be a long - lost shinobi clan re - emerging during the clan wars. They have a unique jutsu that could change the balance of power. Another idea is a young shinobi from a small clan trying to unite all the clans against a common, powerful enemy. And a third could be a clan war being secretly instigated by a group with a hidden agenda.
Well, the shinobi rules in Naruto fanfic can be quite diverse. There's the rule of secrecy regarding jutsu. Shinobi are not supposed to freely share their unique and powerful jutsu with outsiders or enemies. Then there's the code of honor in combat. They should fight fairly, not use underhanded tactics like attacking an unarmed opponent. And of course, they are required to respect the hierarchy within the village's shinobi system.
Perhaps it's a shinobi who has retired after a long and eventful career. He could be someone who has seen the darker side of the shinobi world and wants to make sure Naruto doesn't go down the wrong path. He might have been a wandering shinobi who finally settles down with Naruto. For example, he could be a shinobi from a different village who has a unique set of skills to teach Naruto.
I'm not sure specifically what that particular 'the last shinobi naruto fanfic' is about as there could be many different interpretations and stories within fanfics. It might be about the last remaining shinobi in the Naruto universe, perhaps their final battles, or their efforts to preserve the shinobi way in a post - apocalyptic or changed Naruto world.
Well, in this kind of fanfic, usually there would be intense battles. Naruto is extremely powerful with his various jutsu like Rasengan. The Shinobi Alliance also has a lot of strong ninjas. Maybe the story would focus on Naruto having to face the combined forces of the alliance due to some misunderstanding. It could also explore Naruto's growth and how he tries to resolve the conflict without causing too much harm.