Ariel is definitely one of the most popular characters. After all, she is the main character in the original story and in the fanfic as well. Writers often focus on her journey and her growth.
You could also create a fanfic where the Little Mermaid meets other mythical creatures on her journey. For instance, she could encounter a group of friendly sea sprites who guide her to a hidden underwater kingdom. In this kingdom, she discovers a way to be with the prince without sacrificing her voice or her mermaid form. It would be a more adventurous and magical take on the original story.
Well, one interesting aspect could be the new interpretations of the characters. In fanfic, writers might give Ariel different motives or backstories that add more depth to her character. For example, they could explore her relationship with her sisters in more detail.
In a Naruto and the Little Mermaid crossover, Naruto could be transported to the underwater kingdom. There, he meets Ariel who is fascinated by his strange powers. Together, they could team up to find a way to stop an evil force that is threatening both the surface world (where Naruto is from) and the underwater world. Naruto's ability to make clones could be used in interesting ways underwater, like creating distractions for the bad guys.
First, do your research on both Naruto's world and mermaid lore. Know the characters, the ninja techniques in Naruto, and the characteristics of mermaids. Then, create a unique plot. For example, combine the idea of chakra with mermaid magic. Make sure your characters are well - developed. If you have a mermaid character, give her a distinct personality, goals, and backstory. Also, keep the Naruto - style action and adventure in the story. Have exciting battles and quests.
Another storyline could be a mermaid who is in love with Naruto. However, there are obstacles because she is from a different world. She has to figure out a way to be with him, and in the process, she uses her mermaid magic to protect the village from an underwater threat that is also affecting the land. This could create a unique bond between her and the villagers.
One idea could be a crossover where the Little Mermaid characters visit Equestria in the MLP world. They could meet the ponies and learn about their magic and way of life. For example, Ariel might be fascinated by the different types of pony magic like unicorn magic. Another idea is a story where a pony discovers a mermaid - like creature in a hidden pond in Equestria and they form an unlikely friendship. It could explore how different their two worlds are yet how they can find common ground.
Maybe a new character, a powerful sea witch who has been influenced by the power - hungry ways of some of Naruto's villains. She wants to rule both the underwater world and the land world above. She would use her magic to create chaos and try to stop Naruto and Ariel from uniting their forces.
Character development is key. Give the Little Mermaid a different personality trait. Maybe she's more of a rebel and doesn't follow the rules of the underwater society as strictly. She could be the one who challenges the old ways and tries to bring about change. This would make her stand out from the original character and make your fanfic more interesting.
A possible plotline could be that Cam and Elizabeth are humans who accidentally discover a magic portal to the underwater world of The Little Mermaid. Once there, they have to adapt to living underwater while also trying to find a way back home. Along the way, they form friendships with the mermaids and sea creatures and get involved in a conflict between Ursula's minions and Ariel's family.