Hulk and a mermaid with strong physical abilities. The Hulk is all about brute strength on land, and the mermaid could have enhanced strength in the water. Imagine if they had to work together to move a huge object that was blocking a passage underwater or on land. The mermaid could use her fins and water currents to help guide the Hulk's massive strength in the right direction, and the Hulk could protect the mermaid from any threats on land.
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 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.
Definitely Superman and Thor. They both have super strength and are associated with powerful, other - worldly elements. Thor has his hammer and lightning powers, while Superman has his super - strength, heat vision, etc. It would be interesting to see them compete in a friendly strength - based challenge or fight side by side against a really strong foe.
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.
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.
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.
Definitely Thor and Tsukiyama. Thor, the god of thunder, with his powerful hammer, and Tsukiyama, the flamboyant ghoul. Tsukiyama's refined tastes and his kagune skills could be paired with Thor's brute strength. They could have some hilarious banter as they fight side by side against enemies. And also, Black Widow and Touka could be a great pair. Black Widow's spy skills and Touka's street - smart and combat - ready nature would make them a formidable duo.
I think Thor and Carlisle would be really interesting. Thor is a god with all his power and Carlisle is an old - school vampire with a strong moral code. They could have some deep conversations about life, death, and power. And then there's Jacob and Bruce Banner. Jacob's hot - headedness and Bruce's struggle with his inner Hulk could lead to some intense situations. Maybe Jacob could help Bruce control the Hulk in some way, or they could get into a big fight that the others have to break up.
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.
A werewolf and Zero from Vampire Knight would be an interesting combination. Zero has his own internal struggle with his vampire side, and adding a werewolf into the mix could either be a source of conflict or an unexpected ally. The werewolf's wild and free nature might contrast with Zero's brooding and complex personality.