One interesting storyline could be about a young owl in the Legend of the Guardians world who discovers a hidden power within itself. Maybe it's the ability to communicate with other animals in a unique way, which then leads it on a journey to find out more about this power and how it can use it to protect the owl kingdom.
One interesting storyline could be about an owl from a different region joining the Guardians and having to adapt to their ways. For example, an owl from a very cold climate coming to the Guardians' warm forest base. Another could be a story where a young Guardian - in - training discovers a hidden power within themselves that no one else has. And a third could be a fanfiction where the Guardians have to face an enemy that uses a new type of magic they've never encountered before.
One interesting storyline could be Prince Peter leading the Guardians on a mission to a long - lost planet filled with ancient technology. This technology could be both a great power source and a danger if it falls into the wrong hands.
One interesting storyline could be Emrys' journey to discover his true powers. Maybe he starts off as an ordinary person but then gradually realizes he has some extraordinary abilities that are tied to his heritage.
Some fanfictions focus on Naruto having a different upbringing. For instance, if he was raised by a different clan, like the Hyuga. This would give him access to their unique abilities and fighting styles. He could also have a different set of friends and rivals, which would completely reshape his character development and the overall plot of the story.
One interesting storyline could be the discovery of a new and extremely powerful Pokemon species that the Ultra Guardians have to figure out how to handle. It could be a Pokemon with unique abilities that pose a threat to the existing ecosystem in the Pokemon world.
Another great storyline could be about a character from Naruto ending up in the world of The Legend of Korra and having to adapt. Maybe Sasuke somehow gets transported there and has to learn about the new bending techniques and how to fit into this different society. He could end up sharing his ninja skills with the benders and creating a whole new form of combat.
Well, in some fanfictions, there are storylines centered around Korra's relationships. Maybe she falls in love with a non - bender, which causes a stir in the bending community. Or perhaps she has to repair a broken friendship with one of her old allies. Also, a great storyline could be Korra having to deal with the political unrest in the Avatar world. She could be in the middle of a power struggle between different nations, trying to bring peace through her avatar powers.
A great storyline might be a pre - Korra story in the Legend of Korra world but with a Star Wars - like epic space battle feel. Imagine the Water Tribes having a large - scale naval battle against an invading force, with ships and strategies inspired by Star Wars, but with the unique bending abilities of the Avatar world thrown into the mix.
One interesting storyline could be Fi and Ghirahim being forced to team up to face a greater threat in the Zelda universe. Maybe a new, powerful dark force emerges that neither of them can defeat alone, so they have to put aside their differences.
One popular storyline is about the backstories of the characters. For example, stories that explore Rocket's past as an experiment are quite common. Another is the relationships between the Guardians, like the budding romance between Star - Lord and Gamora. There are also many fanfictions that deal with the Guardians facing new threats that are not in the movies, such as ancient cosmic entities.