Love and relationships are also popular themes. The h2o characters might fall in love with characters from the other crossover story. This could create interesting relationship dynamics and storylines, like a mermaid falling for a human from a different fictional world.
One common theme is friendship turned into love. Since Bella and Will are friends in the h2o universe, many fanfictions explore how that friendship can gradually develop into something more romantic. Another theme could be adventure. They might go on some underwater adventures together that strengthen their bond.
One common theme is friendship. Since they are both part of the h2o world, their friendship is often explored. They might support each other through tough times, like when dealing with other characters who don't understand their mermaid/merman nature.
One common theme is friendship. Since they are both well - known in the online gaming community, many fanfictions explore their friendship, how they met, and the adventures they have together. Another theme is teamwork, especially in the context of the games they play.
Once upon a time in the underwater world where the mermaids from H2O and Mako Mermaids co - existed. A group of mermaids from both series decided to have a friendly competition. The H2O mermaids showed off their unique ability to turn water into different shapes, while the Mako Mermaids demonstrated their incredible speed in the water. As they interacted, they learned new things from each other and became great friends, vowing to protect the ocean together against any threats.
In this fanfiction, the mermaids from H2O could be discovered by the Avengers. Maybe the Avengers are on a mission near the beach where the mermaids live. The mermaids' unique abilities, like controlling water, could be mistaken for a new threat at first. But then they realize they can work together. The mermaids could use their water powers to help the Avengers during a big battle against a water - based villain like Namor. They form an unlikely alliance and learn from each other's worlds.
It could be about the characters from Harry Potter finding themselves in the world of H2O. Maybe Harry and his friends end up at the beach where the H2O mermaids are. They could learn about the mermaids' powers and secrets, and the mermaids could be fascinated by magic from the wizarding world.
In these fanfictions, the theme of transformation is quite common. The OC might transform in some way, either in their personality or in their understanding of the world because of their encounter with the mermaid. Another theme is the power of friendship. Alongside the love story, the mermaid and the OC could form strong friendships with other characters in their respective worlds. And a theme of mystery also exists. The mermaid's world is full of secrets, and the OC is constantly trying to understand it, which adds an element of mystery to the overall story.
Maybe a magical item gets lost that is crucial to both the H2O and Mako Mermaids' worlds. It could be a pearl that has the power to keep the balance of the ocean's magic. A young mermaid from H2O and a young mermaid from Mako accidentally cross paths while looking for it. At first, they are suspicious of each other. But as they search together, they start to understand each other's powers better. The H2O mermaid can freeze water to access hidden caves, while the Mako Mermaid can use her singing to call upon sea creatures to help. Eventually, they find the pearl and in the process, they create a friendship that bridges the gap between their two worlds.
One idea could be that the mermaids from H2O meet the vampires in Twilight. Maybe they form an unlikely alliance to fight a common enemy, like a group of powerful witches. The mermaids could use their water powers and the vampires their super strength and speed.
Sure. You can check out websites like Archive of Our Own (AO3). There are often some interesting h2o crossover fanfictions there. Just search for 'h2o crossover' in the search bar, and you'll get a list of relevant works. Some crossovers might be with other mermaid - themed shows or fantasy stories.