One idea could be exploring the backstories of minor characters during the war. For example, how the war affected the normal villagers who were not shinobi. Another could be a story where a new, unexpected alliance forms between different ninja clans to fight a common, greater threat that was overlooked during the original war.
One idea could be exploring the backstories of minor characters during the war. For example, how the normal shinobi were feeling and what they were doing on the sidelines. Another could be a what - if scenario where a different alliance was formed among the shinobi villages.
One idea could be focusing on a young shinobi who is an unknown hero during the war. They might use some unique and forgotten jutsu to turn the tide in crucial battles.
One idea could be focusing on a young, unknown shinobi who rises to prominence during the war. They might have a unique jutsu that catches everyone's attention.
In a Naruto 4th Shinobi War fanfiction, we could have a plot where the Akatsuki actually had a hidden agenda that was not related to the tailed beasts at all. They could be using the chaos of the war as a distraction to perform some other dark ritual. And perhaps a young shinobi discovers this and has to race against time to stop them while also fighting in the war.
One idea could be focusing on a young and inexperienced ninja who gets thrust into the chaos of the Third Shinobi War and has to quickly learn to survive. Maybe they form an unlikely alliance with a ninja from an enemy village because they both realize the senselessness of the war at a personal level.
Maybe in the fanfiction, the time travel causes a mix - up of jutsu knowledge. A character from the future accidentally gives the wrong kind of jutsu knowledge to a past - self or another character during the Fourth Shinobi War. This then leads to new and unforeseen strategies being developed by the shinobi, either for good or bad, depending on how it's used. It could completely change the power dynamics in the war.
One interesting plot point could be Naruto's struggle with his new godlike powers. He might find it difficult to control them at first, causing some chaos on the battlefield. For example, he tries to heal a comrade but accidentally uses too much power and ends up giving them some sort of super - ability that they can't handle. Another plot point could be how the other shinobi react to his sudden transformation. Some might be in awe, while others might be jealous or even afraid.
One idea could be exploring the backstories of minor characters during the war. For example, how a random shinobi from a small village coped with the chaos. Another could be a what - if scenario, like what if a certain alliance was formed differently. Maybe a group of rogue ninjas decided to side with one of the major villages instead of staying neutral.
One idea could be to focus on a young and inexperienced ninja who gets caught in the middle of a major battle during the Third Shinobi War. They could witness the horrors of war and have to quickly learn to survive. Maybe they form an unlikely alliance with a ninja from the enemy side who also has a different view on the war.
I think Obito could be really interesting. His complex backstory and his role in the war were so crucial. You could explore his internal struggle further, like his lingering feelings for Rin and how that influenced his actions during the war in more depth.