'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.
Rock Lee could be an interesting main character for a Third Shinobi War fanfiction. Since he doesn't rely on ninjutsu, his unique fighting style could be a great asset during the war. We could see him face off against powerful ninjutsu users from other villages and prove that taijutsu is just as effective. Also, his unwavering determination could inspire his comrades during the dark times of 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.
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.
I don't know for sure as I haven't read it. But it could feature Naruto as a main character since it's related to the Naruto universe. Maybe it also includes his mentors like Iruka or Kakashi who could play important roles in the exploration of the nindo.
The new fanfic might have unique character developments based on the nindo concept. It could also introduce fresh plot twists and challenges for Naruto and his friends.
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.
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 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.
Rock Lee is often overlooked in some of the larger war - time stories. His unique taijutsu skills could be really interesting to explore in the context of the Fourth Shinobi War. He could take on some really tough opponents and show off his growth.