Luke Skywalker and Marty McFly are often popular choices. Luke's heroism and Jedi powers combined with Marty's relatable and adventurous nature can make for great stories. Another popular combo is Darth Vader and Doc Brown. The contrast between the dark, powerful Sith Lord and the eccentric inventor can create a lot of drama and humor in a fanfiction.
Princess Leia and Lorraine Baines McFly. Princess Leia's strong leadership and political acumen could be an interesting contrast to Lorraine's more domesticated yet still feisty personality. And Han Solo and Biff Tannen is also a somewhat unexpected but interesting crossover. Han's roguish charm against Biff's bully - like behavior could lead to some exciting confrontations in a fanfiction story.
Yoda and Doc Brown. Yoda's wisdom of the Force and Doc's scientific knowledge are two very different forms of intelligence. A fanfiction could explore how they might interact and learn from each other. Maybe Yoda tries to understand Doc's time - travel technology through the Force, or Doc tries to explain the scientific principles behind it to Yoda in a way that Yoda can relate to.
Han Solo and Commander Riker are also often crossed over. Han's roguish charm and piloting skills combined with Riker's military strategy and charisma make for an exciting pairing. They could be on a mission together, trading quips and sharing their different experiences from their respective universes. Another popular crossover is between Luke Skywalker and Spock. Luke's connection to the Force and his journey to become a Jedi, compared to Spock's logical Vulcan upbringing, offers a lot of room for character development and interesting interactions in fanfiction.
Hermione Granger and Hera Syndulla are often crossed over. Hermione's intelligence and vast knowledge of magic can be paired well with Hera's leadership and piloting skills. Also, Han Solo and Ron Weasley are popular choices. Their roguish charm and sense of humor are quite comparable, and fanfiction writers like to explore how they would get along or what kind of adventures they would have together.
Popular characters for crossovers include Goku. He's known for his amazing strength and transformations, which would be fascinating in the Star Wars world. Then there's Darth Maul. His double - bladed lightsaber and acrobatic fighting style could be an interesting match for the high - flying and fast - punching Dragon Ball Z characters. Also, Master Yoda. His wisdom and unique use of the Force could interact in an interesting way with the martial - arts - based combat of Dragon Ball Z characters.
Harley Quinn and Rey could be a popular crossover. Rey is a strong female character in Star Wars, and Harley Quinn has a very distinct personality. A fanfic could explore how Rey's determination and Harley Quinn's chaos - loving nature would interact, maybe they team up to take on a group of bad guys in a very unorthodox way.
One way to write this fanfic is to think about the themes. Both Back to the Future and Star Wars deal with the idea of destiny. So, your story could revolve around how Marty's destiny in his own universe is somehow linked to the fate of the Star Wars galaxy. You could also play with the concept of time differently in the two universes. In Star Wars, there's a more linear view of time in a sense, while in Back to the Future, time - travel is a central mechanic. Combine these ideas to create an interesting narrative. For instance, what if Marty's actions in the Star Wars universe change the future of his own world in unexpected ways?
Luke Skywalker and Amuro Ray would make an interesting crossover. Luke's Jedi skills and Amuro's Gundam piloting abilities could lead to some great action scenes. They could learn from each other, like Luke teaching Amuro about the Force and Amuro showing Luke the ins and outs of Gundam technology.
Anakin Skywalker and Aang are quite popular. Anakin's journey from a young Jedi to Darth Vader could be paralleled with Aang's growth as the Avatar. They both have a lot of power and face internal struggles. Also, Luke Skywalker and Korra could be an interesting crossover. Luke's hero's journey could be compared to Korra's as she overcomes various challenges in her world.
Another popular trope is the 'power transfer'. In some fanfictions, the idea is that the time - traveling capabilities from Back to the Future could somehow interact with the Force in Star Wars. Maybe a character from Back to the Future gains the ability to use the Force because of a time - space anomaly, or a Star Wars character gets access to time - travel technology and uses it in unexpected ways to change the course of the galaxy's history.
Edward from Twilight could be a likely candidate. His brooding nature and special abilities might make for an interesting interaction with the Jedi or Sith in Star Wars. He could either be seen as a potential threat or an ally. Another would be Ahsoka Tano from Star Wars. Her strong will and combat skills could be interesting when pitted against the vampires of Twilight.
Fiona is also a top choice. Her relationship with Shreck in the movies gives a lot of material for crossovers. Fanfiction writers might explore how she and Shreck interact in different universes or scenarios, like in a world where they are not in the same fairytale but a different, more modern world.