Perhaps there is a prophecy in the Naruto - Star Wars crossover world that foretells of a 'chosen one' who will combine the powers of the ninja and the Force. Naruto, believing he can use this power for good, starts to explore the dark side of the Force unknowingly. Slowly, he is corrupted and transforms into a Darth Vader - like figure. His Sharingan (if he had one in this fanfiction) could turn red like Vader's Sith eyes, and he would use his newfound powers for his own, often cruel, means.
One possible plot could be that Naruto, through some strange magical or technological accident, gets transported to the Star Wars universe. There, he is influenced by the dark side of the Force and starts to take on the characteristics of Darth Vader. Maybe he has a run - in with Palpatine - like figure who manipulates him. He could start wearing Vader - like armor as a symbol of his new, darker self.
Well, one possibility is that Naruto, with his ninja skills and positive attitude, clashes with Darth Vader's dark and authoritarian ways at first. But as time goes on, he might learn some unique combat techniques from Vader while also trying to influence Vader with his own values of friendship and loyalty.
One way this could happen is through some sort of interdimensional rift. Maybe a powerful jutsu in the Naruto universe accidentally tears open a portal to the Star Wars galaxy. Naruto, being the curious and brave ninja he is, gets sucked into it. Once in the Star Wars universe, he's exposed to the dark side of the Force, which gradually corrupts him and he starts to take on the persona of Darth Vader. He might even learn some of the Sith ways from Vader's own teachings if he somehow travels back in time to Vader's era.
One possible plot could be Naruto finding an ancient scroll that tells of a powerful being from another world like Darth Vader. He becomes obsessed with learning more about Vader's power and starts to train in a more aggressive way inspired by Vader.
In a fanfic, perhaps Darth Vader is reborn in the Naruto world as a ninja. He has no memory of his past as Vader at first. As he grows up, he discovers he has strange powers that are different from normal chakra. Eventually, he starts to regain his memories bit by bit and has to decide whether to embrace his Sith past or fully embrace the ninja way of the Naruto world.
Well, the plot could be that Naruto, through some dark magic or strange time - space anomaly, gets the powers and persona of Darth Vader. He might start ruling the Hidden Leaf Village with an iron fist, suppressing any form of opposition. His friends would be shocked and some might try to bring the old Naruto back. It would be a total shift from his usual positive and friendly self to a dark and menacing figure.
Maybe Naruto gets transported to the Star Wars universe and somehow becomes like Darth Vader. He could start using the dark side of the Force while still having his ninja skills.
In the 'naruto is like darth vader fanfiction', their journey of self - discovery could be seen as similar. Naruto has to constantly figure out his place in the ninja world and how to control his power. Darth Vader is on a journey of self - discovery too, as he grapples with his identity as Anakin Skywalker and his role as Darth Vader. They also have a sense of isolation in some ways. Naruto often feels alone in his struggles, and Darth Vader is isolated in his dark armor, cut off from his former self and many human connections.
Well, one possibility could be that Naruto, as the son of Darth Vader, might struggle with the dark side of the Force within him while also trying to uphold the values of the ninja world. He could have unique powers that combine the Force and ninja techniques.
In the 'Darth Vader travels to the future fanfiction', it could be that he ends up in a future where the galaxy is at peace. There are no wars, and the Jedi have evolved into something different. Vader, being from a time of conflict, struggles to adapt. He may be seen as a relic of a more violent era. However, he also holds knowledge that could be valuable. Maybe he teams up with some future characters to prevent a new threat that is emerging, using his unique skills and the power of the dark side, while also being tempted to turn away from his dark past.
His view of justice would change. Naruto believed in a very straightforward form of justice where the good guys win and protect the weak. But as Darth Vader, he'd be more about maintaining order through fear. He'd use his new - found power in a much more forceful and sometimes cruel way. His relationships would also be different. Instead of having friendly and equal relationships with his comrades, he'd be more of a feared leader. He'd be above them, not on the same level as he was before. His character would lose its innocence and become much more complex and dark.