Well, Galen Marek in Star Wars Rebels fanfiction is a great concept. His relationship with the dark side and his journey back to the light (if that's how a fanfic writer takes it) can be a source of inspiration. He could be a mentor figure to the young Jedi in training like Ezra. His combat skills and knowledge of the Sith could be used to outwit the Inquisitors. Fanfic writers can explore how he adapts to the Rebels' way of life, which is so different from what he has known in the past.
There's a fanfic called 'Galen Marek: Unseen Adventures in the Clone Wars'. This one focuses on the untold stories of Galen Marek during the Clone Wars. It has some exciting action scenes and also gives a fresh perspective on his relationships with other characters in the Star Wars universe.
Well, Galen Marek in a Star Wars Rebels fanfic might be a bit of an anachronism at first glance. But if you think about it, the Star Wars universe is vast. He could have been in hiding for years. In the context of Rebels, he could be a force for change. He might be drawn to the Rebellion's cause because of his own experiences with the Empire's cruelty. His presence could also attract unwanted attention from the Empire, leading to some tense moments in the fanfic. For example, the Inquisitors might sense his power and start hunting him, which could then put the Rebels in danger as they try to protect him.
There are often fanfictions that explore Galen Marek's relationship with other characters in more depth. For example, his interactions with Vader could be expanded upon. What if there were more moments of mentorship or conflict between them that we didn't see? This could make for an interesting fanfiction.
One possible scenario in Galen Marek's time travel fanfiction could be him going back in time to prevent the fall of the Jedi Order. He might use his powerful Force abilities to change key events and save his fellow Jedi.
Archive of Our Own (AO3) is also a great place to search for Galen Marek fanfiction. It has a well - organized tagging system, so you can search specifically for stories related to him. There are often some high - quality and unique takes on his character there.
One idea could be that Galen Marek and Ahsoka Tano team up to face a new Sith threat. They might initially be suspicious of each other due to their different backgrounds. Galen with his training under Vader and Ahsoka's Jedi training. But as they work together, they start to respect each other's skills and form a strong bond.
He can be portrayed as a mysterious figure who arrives to help the Rebels at a crucial time. Maybe he shows up just when they are about to be defeated by the Empire and uses his incredible Force powers to turn the tide. His appearance could be all in black like his usual style, but with a glimmer of hope in his eyes that shows he's on the side of the Rebels now.
One interesting fanfic could be about Galen Marek's early training. It might explore his relationship with his master in more depth than the official story. For example, how he overcame difficulties during training.
Another possible storyline is Galen Marek's exploration of his own identity during the Clone Wars. He might be conflicted between his training as a Sith and his own sense of right and wrong. In the chaos of the Clone Wars, he could start to question the Sith teachings. Fanfiction could explore how he copes with these internal struggles while also dealing with the external threats of the war.