Well, perhaps Naruto could use the lightsaber in his ninja battles. He might combine his chakra control with the unique abilities of the lightsaber. For example, he could infuse his chakra into the lightsaber to make it more powerful or use his ninja skills to perform acrobatic maneuvers while wielding the lightsaber.
The plot could involve Naruto being transported to a Star Wars - like universe where he is given a lightsaber. He meets some of the Star Wars characters and has to learn their ways. Meanwhile, back in his own world, his friends are worried about his disappearance. Naruto then has to find a way to return to his world while also mastering the use of the lightsaber and dealing with any threats in the new universe.
A possible plot could be that Naruto is sent on a special mission to a far - off planet where lightsabers are common. There, he is given a dual bladed lightsaber by a wise old Jedi - like figure. He then has to learn the ways of the lightsaber while also dealing with local politics and power struggles. Back on Earth, his enemies sense his new power and start plotting against him. Naruto must return in time to save his village, using the skills and power he gained from his adventure with the lightsaber.
Well, one possibility could be that Naruto's symbiote gives him enhanced physical abilities. For example, it could increase his speed and strength even more than his normal ninja skills already do. Maybe the symbiote also has some special powers of its own, like the ability to sense danger from a far greater distance. This could add an interesting twist to Naruto's adventures as he would have to learn to control this new power source while still relying on his ninja training and the power of the Nine - Tails.
Well, one possible plot could be that Naruto somehow gets a kagune through some strange experiment gone wrong. He then has to learn to control this new power while still dealing with his normal ninja duties. He might face discrimination from some in the ninja world who fear his new and unknown power.
He could find it during one of his missions. Maybe he's exploring an ancient ruin and stumbles upon the lightsaber. It could be in a chest or just lying there, and Naruto, being curious, picks it up.
Perhaps it's given to him by a mysterious figure. This figure could be from another dimension or a very old ninja who has been in hiding for a long time. They recognize Naruto's potential and power, and decide that he is the one worthy of wielding the black lightsaber. This could be part of a bigger plan to help Naruto defeat a new and powerful enemy that neither the ninja world nor the normal means of combat can handle.
Well, one possible plot could be that Naruto somehow gets transported to the Pokemon world with the Nine - Tails still inside him. The Pokemon trainers might initially be afraid of him because of the Nine - Tails' power. But then Naruto could team up with some trainers to fight against an evil organization that wants to capture the Nine - Tails for its own dark purposes. Maybe he'd also learn about Pokemon battling and use some of his ninja skills in those battles too.
The plot could involve Naruto traveling to a world where the All for One quirk exists. There, he meets characters from the My Hero Academia universe who are either intrigued or threatened by him. Naruto, with his natural charisma and strong sense of justice, tries to find a way to co - exist with these new powers and people. He could end up using the All for One quirk in unique ways, like using it to absorb and then redirect negative energy or harmful jutsu, all while trying to bridge the gap between the two very different worlds.
In this fanfic, perhaps the blue lightsaber has some special connection to Naruto's chakra. It could be that the lightsaber was created by an ancient ninja who had some knowledge of a different kind of energy, similar to the Force in the Star Wars universe. Naruto then has to master both his chakra and the power of the lightsaber, and he uses it to protect his village from a new and unexpected threat that can only be defeated with the combined power of his ninja skills and the blue lightsaber.
In the fanfiction, the double lightsaber might be a gift from an unknown entity. Naruto, being the curious and adventurous type, would start training with it. He'd have to learn how to handle the two blades simultaneously, which could be a whole new challenge. This could lead to new forms of combat that blend Naruto's existing fighting styles with the lightsaber techniques.
Naruto's fighting style would likely incorporate more acrobatic flips and spins to take advantage of the lightsaber's reach. He'd also use his shadow clone jutsu in new ways, like having clones surround an enemy while he attacks from above with the lightsaber.