There's also the possibility that a civilian who has no ninja training at all becomes the unexpected hero. They might use their wits and knowledge of the land to help the ninja. For instance, they could lead a group of ninja through a secret passage to avoid an ambush, or they could come up with a strategy to cut off the enemy's supply lines using their understanding of the local economy and trade routes.
Well, one plot twist could be that a minor character turns out to be a powerful spy for the enemy. They've been hiding in plain sight all along, feeding information to the opposing side.
A civilian who somehow gets involved in the war and discovers they have latent shinobi abilities. They could start as a clumsy and inexperienced character but grow into a powerful force.
It could be an original character. For instance, a ninja from a small, unknown village who has a unique power and is forced to participate in the war. They could be the underdog that everyone underestimates at first.
It could be a long - lost relative of Orochimaru. This person might have been secretly studying Orochimaru's forbidden jutsu and developed even more terrifying techniques. They could be seeking revenge on the ninja world for ostracizing Orochimaru.
There could be a new group of villains who emerged from the shadows. They might have been observing the war and learned from the mistakes of previous antagonists. They could be more powerful and cunning, perhaps using new forms of jutsu or technology that were developed during the war. Maybe they are after some ancient artifacts or secrets that were unearthed during the Fourth Great Ninja War.
In a 'Naruto 5th Great Ninja War Fanfiction', the story could start with a strange phenomenon that begins to disrupt the chakra balance in the ninja world. This is a sign of the approaching war. As the war breaks out, the younger generation of ninjas, inspired by Naruto's heroics in the previous wars, step up to fight. They face off against a coalition of rogue ninjas who are being controlled by a shadowy figure with a vendetta against the established ninja order. Along the way, there are many battles, with each side using new and creative jutsus and strategies.
How about Hinata? She could be the main protagonist. In the fanfiction, she could be on a journey to prove herself not just as a member of the Hyuga clan but also as a strong ninja in the Second Great Ninja War. She might discover new abilities and play a crucial role in the war, perhaps even saving the day in her own unique way.
It could be an original character. For instance, a young ninja from a small, unremarkable village who has a strong sense of justice and a hidden potential. This character could be inspired by Naruto's own journey, starting from being underestimated but growing into a powerful force during the war.
Well, I really liked the fanfiction titled 'Alliances Reimagined' in the 'Naruto 4 Great Ninja War' context. In this one, new alliances are formed that completely shift the dynamics of the war. Then there's 'The Hidden Powers'. It explores some hidden powers that characters discover during the war and how they use them to turn the tide. 'The Hope Beyond War' is also a great read. It's about the hope and rebuilding that follows the end of the 4 Great Ninja War.
Sasuke could also be the main character. His quest for power and revenge could be further explored in the context of the war. He might find himself in situations where he has to choose between his personal goals and the greater good of his village and the shinobi world.