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.
The plot should be engaging. It could add new twists to the Naruto vs Pain battle. Maybe introduce some new jutsus or strategies that make the fight even more exciting. Also, good fanfictions in this category usually have a good balance between action and the emotional aspects of the characters.
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.
'The Unseen Hero of the 4th War' is a great one. It focuses on a character who is often overlooked in the original story but plays a crucial role in the fanfiction. The writing style is engaging and it really dives deep into the character's emotions during the chaos of the war.
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.
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.
A third idea is a story centered around a shinobi who was thought to be dead but actually survived and is now trying to get back to the battlefield. Along the way, they discover secrets about the origin of the war or new jutsu that could turn the tide of the battle. They have to overcome their own physical and mental weaknesses while also evading the enemy who believes them to be dead.
The 'little owl little owl flannel story' might be a story designed for kids. Flannel could be used as a medium to make the story more vivid, like using flannel to create little owl puppets or a flannel - made background for the story. It could be about the little owl's growth. The little owl might start as a curious and a bit clumsy youngster. It gradually learns important skills such as flying better and hunting more effectively. And throughout the story, it could also teach children values like courage and perseverance.