One interesting fanfiction could be about Darth Vader secretly having a moment of hesitation when facing a Rebel who reminds him of his past self. Maybe he lets the Rebel escape without the Emperor knowing. It adds a new layer of complexity to his character.
There might be a fanfiction where Darth Vader teams up with a Rebel in a strange turn of events. They have to fight a common enemy that is a threat to both the Empire and the Rebellion. This would explore the idea that sometimes enemies can find common ground. It could involve a lot of tense dialogue as they learn to trust each other just enough to complete their mission.
One interesting story could be about Darth Vader secretly having a change of heart during the events of Star Wars Rebels. Maybe he has a brief encounter with a Rebel that makes him question his loyalty to the Empire.
In a fanfiction, Darth Vader might finally face his past with Ahsoka. Maybe he would have moments of hesitation in their battles, as memories of their time as master and apprentice resurface. This could lead to an internal struggle within Vader, torn between the Dark Side and his former self.
In some fanfictions, Darth Vader's redemption is linked to his relationship with his daughter, Leia. Maybe he discovers her identity before the events in 'Return of the Jedi' and starts to change his ways in order to protect her and make amends for his past actions. He could start to undermine the Empire from within to ensure her safety.
Ezra Bridger would be a great character to pair with Darth Vader. Their interactions could be really intense, as Ezra is a powerful young Jedi in the Rebels series and Vader has a history with the Jedi. It could lead to some great battles and also some interesting moments of understanding or misunderstanding between them.
Kanan Jarrus is another good choice. As a Jedi, he has the skills to face Vader, at least to some extent. Their interactions could explore the differences between the Jedi way and the Sith way. And Kanan's relationship with his crew could also play into the story, as he tries to protect them from Vader's wrath.
Ezra's reaction would also depend on his state of mind at the time. If he was feeling confident and strong in the Force, he might be more bold in his approach to Vader. He could try to engage in a battle of wills through the Force, trying to push back against Vader's dark side influence. But if he was already weakened or doubting himself, the sight of Vader could make him feel hopeless and desperate, leading to a more erratic or panicked reaction.
Well, a cool plot might be that Ahsoka gets trapped in a Sith - created illusion world by Vader. In this world, she has to face her past traumas and fears related to Anakin's fall. Meanwhile, Vader is conflicted as he watches her struggle, memories of his past with Ahsoka resurfacing. Or there could be a story where they both are on a mission to retrieve a powerful Jedi/Sith artifact, and their paths cross in a race against time.
In fanfiction about Ezra and Darth Vader, their interactions could also be more psychological. Vader could try to tempt Ezra to the dark side. He might offer Ezra power, saying that with his potential, he could become a great Sith. Ezra, on the other hand, could resist and try to turn Vader back to the light, using his own experiences and the teachings of the Jedi he has learned. This back - and - forth of wills could create a really engaging and complex story line.
There could be a fanfiction where Vader has an unexpected alliance with a rebel. Maybe they are forced to work together to stop a greater threat, like a rogue Sith or a powerful alien race that wants to destroy both the Empire and the Rebellion. This would put Vader in a complex situation as he has to deal with his loyalty to the Emperor and his newfound, albeit temporary, partnership with the rebel.
Another story is about Vader's relationship with his son, Luke Skywalker. Vader was initially set on turning Luke to the dark side. But in the end, his love for his son redeemed him. There were many encounters between them, like the one on Cloud City, where Vader revealed to Luke that he was his father, which was a huge shock in the Star Wars saga.