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.
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.
Another possibility is that the black lightsaber has some sort of special power or property that ties into the Naruto universe's existing powers. For instance, it could be attuned to chakra in some way. Maybe it can be powered by chakra instead of the typical energy source in the Star Wars universe. This would create an interesting dynamic as Naruto characters would have to learn how to manage this new form of power while still using their own ninja abilities.
Well, he might find it in some mysterious place like an ancient temple. Maybe it was left there by a powerful being from another dimension.
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.
He might gain the ability to cut through almost anything. The black lightsaber, being a powerful weapon, could enhance Naruto's already formidable combat skills. He could use it to slice through strong jutsu defenses with ease, something that normal kunai or shuriken couldn't do.
If Naruto wielded a black lightsaber in fanfiction, he would likely be an even more formidable opponent. His already impressive combat skills combined with the power of the lightsaber would make him a force to be reckoned with. He could use his speed and agility to quickly strike with the lightsaber, and his strategic thinking would allow him to use it effectively in battles.
Well, in some fanfictions, Naruto might obtain the black wings through a special chakra infusion. Maybe it's a result of some ancient Uzumaki clan power that was dormant within him and got awakened in a moment of extreme need, like when facing a powerful enemy.
The black lightsaber has a unique and interesting story. It was created by Tarre Vizsla, the first Mandalorian to become a Jedi. It's a symbol of power and has passed through different hands over time, often being associated with important events in the Star Wars universe.
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.
On the positive side, it might inspire new technology in the ninja world. The unique energy and design of the lightsaber could give the ninja inventors new ideas. For example, they could try to create a similar type of weapon that uses chakra instead of the lightsaber's energy source.