A plot could involve the female stormtrooper being part of an experiment by the Empire that gives her some unique abilities. Darth Vader becomes aware of these abilities and decides to use her in his own plans. At first, she is hesitant, but as she spends more time with Vader and sees his power and his vision for the Empire, she starts to believe in his cause and becomes an important part of his operations. She might even help him in battles against powerful Jedi who oppose the Empire.
Well, perhaps the female stormtrooper witnesses Darth Vader performing some act of incredible power. She becomes intrigued and starts to follow him secretly. Eventually, Vader notices her and tests her loyalty. She passes his tests and he then assigns her special missions that no other stormtrooper could handle, like infiltrating a rebel base that has some sort of dark side artifact he desires.
The relationship could start with the female stormtrooper showing great combat skills that catch Darth Vader's attention. He then begins to give her more difficult tasks, and in the process, they develop a mutual respect. For example, she could be the only one in her unit to survive an ambush, and Vader sees her determination.
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.
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.
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.
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.
It could be that Darth Vader is intrigued by C3PO's unique design and programming. Since C3PO has been around different planets and species, Vader might try to extract knowledge about various cultures and technologies from him. C3PO, being a protocol droid, would be full of such information. Their meeting could lead to a series of interrogations where C3PO tries to evade Vader's questions while Vader uses his dark side powers to intimidate him.
Well, one possible plot could be that Darth Vader tries to persuade Luke to join the dark side once again. Maybe he shows Luke some 'truths' about the Jedi that he believes are lies, trying to shatter Luke's faith in the Jedi way.
One aspect of Darth Vader's full potential in fanfiction could be his ability to break free from the Sith's influence completely. He might then use his skills for good, perhaps even training a new generation of Jedi. His combat skills, already top - notch, could be enhanced to the point where he could defeat multiple enemies single - handedly.
Padmé could be a main character. Since Darth Vader is without his suit, it could be a scenario where he's reliving memories of her, and she could appear as a Force ghost or in his dreams, guiding him in some way. Another character could be Obi - Wan Kenobi. Their relationship was complex, and without the suit, Vader might be more vulnerable, and Obi - Wan could try to sway him back to the light side.