In a Naruto - based fanfiction, the female swordsman criminal could be a former member of a rogue ninja group. She decides to turn over a new leaf after realizing the error of her ways. However, the shinobi world doesn't trust her easily. She uses her swordsmanship not only to defend herself but also to prove that she can be a force for good. For example, she might start by helping villagers who are being attacked by bandits, gradually earning their trust and respect.
There could be a fanfiction where the female swordsman is a criminal because she stole a powerful, ancient sword that was said to hold great power. In the Naruto universe, this sword is highly coveted. She believes that the sword can be used to bring balance to the world, but the ninja villages see her as a threat. As she evades capture, she meets Naruto and his friends. Naruto, with his belief in redemption, tries to understand her motives and might even help her in her quest, depending on how the story unfolds.
She could be a criminal because she was born into a family that was considered enemies of the Hidden Villages. Her swordsmanship was passed down through generations in her family. As a result, she has to fight against the prejudice and the constant pursuit of the ninja. She might find an unexpected ally in a young, open - minded ninja who sees her for who she really is, not just as a criminal.
Sasuke could be one. Since they have a long - standing rivalry, Sasuke, with his own powerful skills, would be a great opponent for Naruto now that he's a master swordsman. They could have an epic battle where sword meets sword and their respective powers clash.
One potential ally could be Neji. Neji has his Byakugan and his skills in combat. He could see the dark swordsman as an equal in terms of combat ability and form an alliance. Also, Tenten, who is fascinated with weapons. The dark swordsman's sword and his skills with it could draw Tenten's interest, and she might become an ally. They could exchange knowledge about different weapons and fighting techniques.
Iruka could be his mentor. Iruka has always been there for Naruto from the start. He could teach Naruto the basics of swordsmanship, using his knowledge of the ninja arts. Iruka would be patient and understanding of Naruto's blindness, helping him to develop other senses to compensate for his lack of sight.
One possible fanfic could be about a character who wields a unique sword with special powers. Maybe it's a hidden clan member who has been training in secret all this time and emerges as the strongest swordsman. They could use their sword skills to fight against powerful enemies like the Akatsuki members, adding a new and exciting dynamic to the Naruto universe.
Shikamaru could also be an ally. His intelligence would be invaluable in planning strategies and outwitting the more cunning criminals. He could help Naruto figure out the complex power structures within the underworld and come up with plans to either take them down or use them to Naruto's advantage.
It could be Sasuke. He already has great combat skills and if he were to focus more on swordsmanship, he could be a very strong swordsman. His Sharingan would give him an edge in predicting his opponents' moves and countering them effectively with his sword.
One popular original character could be a female swordsman with a unique sword - style that combines speed and grace. Another might be an older, grizzled swordsman who acts as a mentor to the younger generation. There could also be a mysterious swordsman with a hidden past and a sword that has strange markings.
A plot could be that the female swordsman was experimented on by Orochimaru and turned into a criminal as a result of the dark chakra infused in her. She uses her sword to hunt down those who once supported Orochimaru's experiments. Her criminal actions are more about seeking justice in her own distorted way.
One possible plotline could be Naruto losing his sight in a battle but then discovers his latent swordsmanship skills. He might train under a master swordsman who helps him adapt to his blindness. Another could be that Naruto is born blind but has an extraordinary sense of hearing and smell which he uses to become a great swordsman. He could face discrimination from some in the ninja world at first because of his disability, but prove them wrong with his skills.