Well, it could be that the characters go on separate adventures that further develop their skills. Maybe Ezra discovers new Force abilities that he uses to help the Rebellion in unexpected ways. He might meet new allies or face new villains.
Another possibility is that the story delves deeper into the backstories of some of the minor characters. For example, we could learn more about Zeb's past and how it has shaped his views in the present. This could add more depth to the overall narrative and give us a better understanding of the Star Wars Rebels universe within the context of the fanfiction.
Maybe an Imperial officer who is extremely cunning and ruthless. He might be obsessed with hunting down the Rebels and has a personal vendetta against them. He could use underhanded tactics and his knowledge of the Empire's resources to cause trouble for our heroes.
It's also possible that their reunion would be more hesitant. With so much history between them, they might be a bit guarded at first. But as they start to interact more, the old feelings would slowly resurface, leading to a gradual rebuilding of their relationship.
He could be kidnapped by a group of pirates who mistake him for someone else. These pirates are known for their ruthlessness. The rebels would need to negotiate with other pirate groups to get information about Ezra's whereabouts. It would be a story full of danger and unexpected alliances.
Ezra could be tortured for information about the Rebellion. The Empire would be eager to know Rebel plans and bases. His capture might also lead to the discovery of some of the Rebels' secrets if he accidentally reveals something under duress.
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 a fanfiction, Ezra's injury could lead to a power shift within the Rebellion. With him out of commission, others might have to step up and take on his responsibilities. This could cause some internal conflict as different characters vie for leadership or try to fill his shoes. Meanwhile, Ezra is struggling with his injury and trying to recover in time to prevent the Rebellion from falling apart or being defeated by the Empire.
Perhaps Sabine finds Ezra on a planet that is filled with dark side energy. Ezra has been struggling to resist it. Sabine has to not only rescue him but also help him cleanse the dark side influence from his mind. This would involve a lot of emotional and spiritual growth for Ezra, with Sabine as his support.
In such a fanfiction, there would be a lot of culture clashes. The Avengers are used to their Earth - based battles and technology. When they meet the Star Wars characters, they'd have to adapt. For example, the Hulk might not understand the concept of the Force at first and just smash things around. But then, he could learn to use it in his own way. The Star Wars characters would also be shocked by the Avengers' powers. Luke Skywalker might be inspired by Iron Man's suit and try to create something similar for himself.
One possibility is that Ezra's connection to the Force becomes stronger. Ahsoka could teach him how to meditate more effectively, which would deepen his bond with the Force. This could lead to him being able to perform more powerful Force feats, like moving larger objects or sensing things from a greater distance.
In the fanfiction, Ezra and Luke could form a strong friendship. Ezra could introduce Luke to some of the friends he made in the Rebels, like Sabine or Zeb. This could expand Luke's understanding of the different groups fighting against the Empire. They could also train together, with Ezra showing Luke some of the unique Force abilities he has discovered. And perhaps, they could even come up with a new strategy to take on the Empire's more powerful weapons or leaders.