It could be that Naruto is transported to a magical world where he discovers the wizard sword. Maybe he has to learn how to use its magic powers to get back to his own world.
You can try searching on popular fanfiction websites like Fanfiction.net or Archive of Our Own (AO3). Just use the keywords 'Naruto' and 'wizard sword' in their search bars.
Perhaps it's a staff that amplifies the user's chakra and also has wizard - like spells inscribed on it. The staff might be able to summon mythical creatures from the wizarding world to aid Naruto in battle. It could also have the ability to teleport Naruto short distances, which would be a great advantage in combat.
One possible scenario in this fanfic could be that Naruto finds a magical sword. The sword might have special powers like being able to cut through any material or even having the ability to nullify jutsu. Naruto, being Naruto, would initially be confused about how to use it but would soon start to experiment. He might try to incorporate it into his combat style, perhaps using it in combination with his shadow clones to create some really cool and unexpected attacks.
In a 'Naruto Finds a Legendary Sword' fanfiction, a lot can happen. The sword might have a connection to Naruto's family. It could be a heirloom that was lost generations ago. This discovery could lead to Naruto learning more about his family's past and his own heritage. He may also have to go on a quest to fully understand the sword's powers and how to use them. He might meet new allies along the way who help him in his journey. There could be epic battles against those who want to steal the sword from him, and Naruto would have to use his wits and newfound sword skills to defend it.
A possible fanfiction could be where Naruto discovers the sword in an ancient temple during a mission. The sword has inscriptions that are only readable by those with pure hearts. Since Naruto is known for his good nature, he can read it and unlock the sword's true potential which gives him abilities like enhanced speed and strength.
If Naruto finds his mother's sword in a fanfiction, it might lead him on a journey of self - discovery. The sword could be a symbol of his heritage. It could also attract the attention of enemies who either feared his mother or want the power of the sword for themselves. This would then put Naruto in a dangerous yet exciting situation where he has to protect the sword and learn about its significance.
The sword could make Naruto more cautious. Since it's sentient, it might have its own motives that Naruto doesn't fully understand at first. So he has to be more careful about his actions and decisions.