For a Legend of Korra crossover fanfiction, a crossover with the Star Wars universe would be cool. Korra could be on a planet in the Star Wars galaxy and interact with Jedi and Sith. Her bending could be seen as a new form of 'Force - like' power. She might get involved in the struggle between the light and dark side. Also, a crossover with the world of Studio Ghibli. Korra could find herself in the beautiful and magical worlds created by Miyazaki, like in Spirited Away. She could use her bending to solve the problems in those unique settings.
A Legend of Korra and Star Wars crossover would likely have some really cool character interactions. Aang's spirit could meet Yoda's. They could share their wisdom about the balance of the universe. Also, the technology from Star Wars like lightsabers and starships would be fascinating to see in the world of Legend of Korra. How would the people of that world react to such advanced technology? It could lead to some great storylines about adaptation and progress.
When starting a Legend of Korra crossover fanfiction, choose a crossover that interests you. If it's a crossover with the DC universe, think about the differences in the power levels. Korra's bending is different from Superman's powers, for example. Outline the main conflict. Maybe a villain is trying to take over both the bending world and Gotham City. Then, introduce your characters. Write Korra's entry into the DC world in an interesting way. You could have her accidentally transported there. Build up the story gradually, with interactions between Korra and the DC heroes or villains.
Asami could be a key character in many crossovers. Her engineering skills could be valuable in different settings. For instance, in a crossover with a steampunk world, Asami could collaborate with the local inventors, using her knowledge to upgrade their machines and also learn from their technology while still being able to use her martial arts skills when needed.
One idea could be a crossover with another popular fantasy world like 'Harry Potter'. Korra could end up at Hogwarts and have to deal with magic in a completely new way. Maybe she'd use her bending to enhance or counter some spells.
The plot could involve a villain from One Piece using the power of bending against the world of Korra. For example, Blackbeard discovers a way to steal bending abilities and starts causing chaos. Korra, in her quest to stop him, meets the One Piece crew who are also affected by Blackbeard's actions. Together, they combine their skills, with Korra's bending and the Straw Hats' various fighting styles and Devil Fruit powers to take on Blackbeard.
Well, Naruto's shadow clone jutsu could be combined with Korra's earthbending. The clones could be made out of earth, allowing for a whole new type of combat strategy. They could be used to distract opponents while Korra attacks from another angle.
Another plot twist might be a character swap. For example, imagine if Zuko from the Avatar universe was inserted into the Naruto world. His journey of redemption could be paralleled with that of some of the Naruto characters who have also had to overcome their pasts. In the crossover, he could learn ninjutsu and use his firebending in unique ways, creating a whole new set of challenges and relationships.
Aang could be a great crossover character. Since he is from the previous Avatar cycle, his different approach to bending and his more laid - back personality compared to Korra could create interesting interactions. He could offer her wisdom from his own experiences as an Avatar.
One way would be through the concept of power. In Star Wars, the Force is a powerful energy. In Legend of Korra, there's bending. A crossover could show how these powers interact. Maybe benders could learn to sense the Force or vice versa.