A third plotline could be set in an alternate universe where Naruto and Rock Lee were switched at birth. Naruto grows up in Lee's shoes, with Guy as his mentor, and has to deal with not having the Nine - Tails' power. Meanwhile, Rock Lee grows up in Naruto's place, with all the expectations and the power of the Nine - Tails. This would create a completely different story for both characters and explore how their personalities are shaped by their different upbringings.
One possible plotline could be that Naruto, after seeing Rock Lee's determination in a fight, decides to completely change his fighting style. Instead of relying on his shadow clones as much, he focuses on close - combat skills like Lee. This would require him to train intensively with Guy sensei or even Lee himself. It could lead to some epic battles where Naruto surprises his opponents with his newfound skills.
Well, it could be about Naruto adopting Rock Lee's extreme training regime. Maybe Naruto starts training in the way Lee does, like wearing those heavy weights all the time and doing thousands of reps of exercises. This would change Naruto's growth in the story, making him even more physically strong in a different way compared to his normal training with Jiraiya or Kakashi.
One possible storyline could be that Rock Lee and Tenten go on a mission together and during the mission, they face various challenges that strengthen their bond. For example, they might have to protect a village from a group of bandits. Rock Lee's physical strength and Tenten's weapon skills would complement each other, and through this experience, they develop a deeper understanding and friendship.
One possible plotline could be that Lee is seriously injured during a battle with a powerful enemy. Naruto, being the hero he is, arrives just in time. He uses his shadow clones to distract the foe while he gets Lee to safety. Then, Naruto might use his own chakra to heal Lee's wounds, drawing on his experience with the Nine - Tails' chakra. This would show Naruto's growth and his ability to save his comrades.
A plotline could involve Islamic mythology or figures somehow making their way into the Naruto universe. Maybe an Islamic - inspired spirit or entity appears in the Hidden Leaf Village and has to be dealt with, and the characters learn about Islamic beliefs in the process.
One possible plotline could be Naruto ending up in Alois' world and having to adapt to its different rules and power dynamics. He might use his ninja skills in unexpected ways to survive and make a name for himself.
A possible plotline could be Naruto and his friends being transported to the WW2 era. They then use their ninja skills to try and stop the war. Or perhaps they side with one of the Allied forces and help them in their battles. Another plotline could be that a powerful Naruto villain teams up with a WW2 dictator and they create chaos together. The heroes have to then find a way to defeat this unholy alliance.
A plotline for a Naruto Keyblade fanfic could start with Naruto finding a strange Keyblade - like object during one of his missions. As he tries to figure out what it is, he accidentally activates it and is sent to a different realm. In this realm, he meets other Keyblade wielders who help him understand the power of the Keyblade. Meanwhile, back in the Naruto world, his friends are worried about his disappearance and start searching for him. Naruto then has to master the Keyblade and find a way back home while also dealing with any threats in the new world.
A possible plotline is that a powerful villain threatens both Naruto's world and Alita's world. They are brought together by a mysterious force to stop this villain. Along the way, they face many challenges as they try to understand each other's powers and cultures. For example, Alita may not understand the concept of ninjutsu at first, and Naruto may be baffled by her mechanical body.
A really interesting 'Naruto Rock Lee Fanfiction' is 'Lee's Hidden Potential'. In this story, Rock Lee discovers a new form of power within himself that is not related to the normal chakra system. It's a fresh take on his character, and it explores how he adapts to this new power while still staying true to his original values of hard work and perseverance.
One great Naruto and Rock Lee fanfiction is 'The Unlikely Bond'. It focuses on how their different fighting styles and personalities lead to an interesting friendship. They train together and face challenges side by side, which is really exciting to read.