A possible plot is that Naruto's blindness is a result of a powerful enemy's attack. This forces him into a new world of darkness, but also reveals hidden powers within him. He could start to see things in a different way, not literally but metaphorically. His new - found understanding could lead him to be a better leader. For instance, he might be able to understand the pain of the oppressed in a more profound way, and thus fight for their rights more vehemently. His blindness could also be a way to bring out the best in his friends, as they rally around him to support and protect him.
One idea could be that the blind Anbu has a special ability to sense chakra in a unique way. For example, they can detect the slightest change in an enemy's chakra, even if they can't see them physically. This gives them an edge in battle.
Maybe Naruto was born blind in this fanfiction. However, his determination and positive attitude attract a group of girls. They see his inner strength and beauty, and as the story progresses, Naruto trains hard to become a powerful ninja in his own way, and the harem girls are there to cheer him on and help him out in battles.
Another plot could revolve around how he copes with the loss of vision in one eye during his battles. He might have to develop new fighting techniques. Maybe he teams up with a magical creature that can act as his 'extra eye' in a sense, guiding him during duels. This could also lead to a deeper bond between him and the creature.
Another plot could be that Naruto is adopted by an older ninja who has retired from active duty. This ninja has a lot of wisdom and secrets. Under his guidance, Naruto discovers a new power within himself that was hidden all along.
One idea could be Naruto going back in time and meeting his parents when they were young. He could try to prevent their early deaths or change certain events that led to the hardships in his own life. Another plot could be Naruto ending up in the time of the First Hokage, and learning the original ninja ways that were perhaps lost or changed over time. He might also have to deal with the different political situations of that era.
One idea could be a crossover where Naruto's skills are combined with Ori's abilities in the Blind Forest. For example, Naruto could use his shadow clone jutsu to help Ori solve puzzles or fight off enemies more efficiently.
One plot idea could be that Naruto loses his sight during a battle with a powerful new enemy who has a unique jutsu that affects his vision. He then has to rely on his other senses like hearing and smell, much like how real - blind people do. For example, he could learn to sense the chakra flow around him in a more detailed way to 'see' his opponents. Another idea is that his blindness is a result of a curse placed on him, and he has to go on a journey to find a cure while still facing his ninja duties.
Perhaps there's a political conspiracy in the village. Naruto and Shikamaru discover some dark secrets that certain powerful people in the village don't want exposed. So, they are banished to keep them quiet. They then form an alliance with other outcasts and work towards uncovering the truth and returning to the village to set things right. This could involve a lot of action scenes as they fight off those sent to stop them.
One idea could be exploring their family history. Maybe they discover they have a common ancestor who was a powerful ninja. This could lead to them uncovering hidden jutsu or secrets within their family lineage.
In this fanfiction, Naruto and Kakashi are banished because of a prophecy that some in the village misinterpret. The prophecy seems to suggest they will bring doom, but in reality, it's about a different kind of change. While banished, they explore different lands, learn new jutsu from other ninja clans, and eventually return to the village stronger and wiser, proving the prophecy was misread.