One interesting storyline could be Princess Leia and Elsa teaming up. Maybe they use their leadership skills and powers respectively to save both galaxies from a new threat that somehow spans across the Star Wars and Frozen universes. For example, a dark force that freezes planets in the Star Wars galaxy while also causing chaos in Arendelle.
Well, a really cool plot could be that the Frozen world is actually a long - lost planet in the Star Wars galaxy. The characters from Frozen get involved in the Galactic Civil War. Maybe Kristoff, who is used to cold environments, helps the Rebel Alliance on an ice - covered planet. Elsa could also use her ice powers to create defenses against the Empire's attacks, like building ice walls around Rebel bases. And Anna could befriend some of the alien species in the Star Wars universe and convince them to join the fight against the Empire.
I think Luke Skywalker and Olaf would be quite an unlikely pair. Luke is this serious Jedi Knight, trained in the ways of the Force, while Olaf is a carefree, snowman who loves warm hugs. But perhaps Olaf's innocence and positive attitude could teach Luke to not be so burdened by the weight of the galaxy all the time.
Anna and Han Solo would be a great pair. Anna is brave and impulsive, much like Han. Han could teach Anna some of his smuggler tricks, and Anna could show Han the importance of loyalty and family. They could go on adventures together in both the Star Wars and Frozen universes, facing challenges like the Empire's troops in one and the snow monsters in the other.
One interesting 'Star Wars Frozen' fanfiction could be about Elsa using her ice powers in the Star Wars universe. Maybe she teams up with a Jedi to fight against the Sith. Another could be a story where Anna travels to different planets in the Star Wars galaxy in search of a way to save Arendelle.
Elsa is often a very popular character in 'Star Wars Frozen' fanfiction. Her ice powers make for interesting crossovers with the Star Wars universe. Another popular one is Luke Skywalker. People like to write about his reaction to Elsa's powers or how he might train her in the ways of the Force.
A really cool fanfiction idea would be if Kylo Ren somehow ended up in the world of Frozen. He could be initially seen as a threat, but then Elsa realizes that he has some good in him due to his internal conflict, much like her own struggle with her powers. Or perhaps a story where the Ewoks meet the trolls from Frozen. They could exchange their knowledge of the forest and magic respectively.
Starkiller can be a game - changer in Star Wars crossover fanfiction. He can bring his combat skills and Force knowledge to new settings. For example, if he's in a crossover with the Matrix universe, his ability to sense and manipulate the Force could be compared to Neo's ability to control the Matrix.
One possible fanfiction could be about a Sith Lord from Star Wars ending up in the Naruto universe. Maybe he tries to use the Force to control the chakra, but finds that it's a completely different power system. He could then form an alliance with some of the villains in Naruto, like Orochimaru, who are also interested in power and dark arts.
The cultures in both universes are also ripe for exploration in the crossover. The Federation's values of equality and cooperation in Star Trek contrast with the more hierarchical and often morally ambiguous cultures in Star Wars. A story could focus on how characters from each side learn from or clash with the other's cultural norms.