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.
One possible plot could be that the characters from H2O, who have the power to transform into mermaids in water, end up in the wizarding world of Harry Potter. They could be mistaken for some kind of new magical creature. The Hogwarts students might be both intrigued and a bit wary of them. Maybe they could help the students in a Triwizard Tournament task that involves water in some way.
I think the H2O mermaid, Rikki, could be a great focus. She's feisty and independent. If she were to meet Harry Potter, she'd probably be both intrigued and a bit skeptical of his magic. Her interactions with the wizarding world characters would be full of drama and discovery as she tries to understand this new and strange magic.
I think pairing Hermione with one of the H2O girls would be really interesting. Hermione is so studious and knowledgeable about magic, while the H2O girl has her own unique water - related powers. They could learn a lot from each other. For example, Hermione could try to figure out the scientific basis behind the H2O girl's powers, while the H2O girl could show Hermione some new ways to interact with water magically.
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.
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.
Another unique aspect is the exploration of new storylines. Since it's a crossover, the fanfiction writers can create entirely new plots that are not restricted to the original story arcs of either Twilight or H2O. They can make the mermaids interact with the vampires in ways that are unexpected and exciting. For instance, they could team up to fight a common enemy or have conflicts due to their different ways of life. This gives a lot of creative freedom and makes for some really unique reading experiences.
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.
Definitely Iron Man from the Avengers. His high - tech suit and intelligence could be really interesting when combined with the water - based powers of the H2O mermaids. And one of the mermaids, like Rikki, could be a main character too. She's feisty and her power to boil water could create some really cool interactions with Iron Man's technology, like powering up some of his systems in a unique way.