What could be an interesting plot for a H2O and Mako Mermaids crossover fanfiction?

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.

One possible plot could be that the characters from Mako Mermaids end up in a different magical realm where they meet the mermaids from another story. They could team up to face a common threat, like an evil sea witch who is stealing the magic from all the mermaids. They would have to combine their unique powers, like the moon pool powers from Mako Mermaids and the special singing abilities of the other mermaids, to defeat the witch.

The plot could involve a mermaid from Mako getting lost and ending up in the area where the H2O mermaids live. The H2O mermaids would be surprised at first but then help the Mako mermaid find her way back. Along the way, they exchange stories about their experiences as mermaids, like how they got their powers and what they do to keep their identities secret. And in the end, they form an alliance of sorts.

Emma from H2O and Mimmi from Mako Mermaids would be an exciting pair. Emma is the smart and organized one in the H2O group. Mimmi is also intelligent but has a more free - spirited nature. They could work together to figure out some mystery in the ocean world. Maybe they find an ancient mermaid artifact and have to use their combined knowledge and skills to unlock its secrets.

Well, the mermaids could be brought to the surface world due to some sort of magical or scientific accident. And the Avengers, being the protectors of the Earth, would initially be cautious but then realize they can be allies. The mermaids might have some sort of ancient magic that could be used to power up the Avengers' weapons or defenses. Or perhaps there's a common enemy that is after both the mermaids' underwater resources and the Avengers' technology. So they have to team up to stop this greater threat.

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.

Well, perhaps the H2O girls are being chased by some sea monsters that are normally under Percy's jurisdiction. Percy and his demigod friends come to their rescue. In the process, the H2O girls learn about the world of Greek mythology and demigods. They could then join forces to fight off other threats that come their way, like an evil sea god who wants to take over both their worlds.

One possible plot could be that Zac and Lyla are on a mission to save the mermaid realm from an evil force. During this dangerous journey, they grow closer and closer. The kiss could be a moment of celebration after they succeed in their mission, a way to express their relief and newfound closeness.

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.

Zane would be a great character to include. He has his own charm and knowledge of the human world. If he were in a crossover, he could introduce new technology or ideas to the other mermaids. For example, if he crossed over with mermaids who are more primitive in their ways, he could help them modernize their defenses against threats. And he could also learn a lot from their ancient magic and traditions.