There are also plots where a character travels forward in time. Ezra, for example, could travel to a future where the Empire has been defeated but at a great cost. He then has to decide whether to bring back knowledge of this future to his own time or try to change things in the future he has visited. This kind of plot really plays with the idea of fate and free will within the Star Wars Rebels universe.
Another plot could be that a villain from the future travels back to the time of Star Wars Rebels to try and eliminate the Rebels before they become a real threat. This creates a lot of action - packed scenes as the Rebels have to figure out who this new enemy is and how to stop them without the knowledge they have in their own time.
Some Star Wars Rebels time travel fanfics focus on the relationships between the characters. When time travel is involved, characters may interact with their past or future selves. This can lead to some really interesting character development, like Kanan having to come to terms with a future version of Ezra who has changed a great deal due to his time - traveling experiences.
One interesting plot could be a character from the modern era traveling back in time to the pre - Clone Wars era. They could try to prevent certain events that led to the fall of the Jedi Order. For example, they might attempt to expose Palpatine's true nature earlier. Another plot could involve a time - traveling Sith Lord going to the future to gain new powers or technology and then coming back to change the balance of power in the Sith's favor in the past.
Character exploration. Kallus has a complex character arc in Star Wars Rebels. A good fanfic delves deeper into his past, his motives, and his internal struggles. For example, exploring his time as an Imperial agent and how he gradually changes his views.
Well, it often delves into family relationships within the context of the Rebellion. In a galaxy full of battles and politics, the grandpa's role as a family figure gives a sense of warmth and connection. He can pass on traditions and stories that have been long forgotten, adding to the lore of the Star Wars Rebels.
One interesting plot could be a Grey Jedi trying to bridge the gap between the Jedi and the Sith in the Star Wars Rebels era. They might attempt to stop the extreme actions of both sides and find a middle ground for peace in the galaxy.
One plot idea could be Ezra traveling back in time to the Clone Wars era. He could meet Anakin Skywalker and learn from him, which would be a great character development for Ezra. Maybe he'd even get involved in some of the key battles and change the course of minor events, which would then have ripple effects on his own time.
One interesting plot idea could be Kanan traveling back to the time before the Jedi Purge. He could try to prevent certain events that led to the downfall of the Jedi Order. Maybe he meets his old master as a young padawan and has to figure out how to interact without changing the future too much.
One interesting crossover could be the sharing of jutsu and the Force. For example, a Jedi might learn how to use chakra to enhance their connection to the Force. Maybe a Naruto character could be trained in the ways of the lightsaber, using their ninja skills to create unique fighting styles with it.
One idea could be exploring the backstory of a minor character in the series. For example, you could write about how a Stormtrooper decided to defect and join the Rebels. Another plot could involve a new threat that the Rebels have to face, something that even the Empire is not fully aware of. Maybe a powerful ancient Sith artifact is discovered and both the Rebels and the Empire are racing to get it.
One idea could be a crossover with the original Star Wars trilogy characters. Maybe the Rebels crew teams up with Luke Skywalker and Han Solo to take on a new, powerful Sith threat. This would bring together the scrappy underdog feel of the Rebels with the classic heroism of the original trilogy.