What are the possible plotlines in a Harry Potter is a Merman fanfiction?

One possible plotline could be about the Weasley family trying to improve their financial situation. Maybe they come up with a new business idea in the wizarding world, like a magical product that becomes a huge success and changes their economic status. Another could be a story about how the Ministry of Magic regulates the financial system in the wizarding world, and there are some characters who try to manipulate or reform it.

Well, one possible plotline could be a story where a character from the wizarding world, perhaps a powerful wizard, takes on a concubine in a parallel world or an alternate version of the wizarding society. The concubine might be from a different magical culture and their relationship could cause political or social unrest within the wizarding community.

One possible plotline could be that the parrot is a magical pet of a new character who enters Hogwarts. This parrot has the ability to detect dark magic, so it helps the students in their fight against the forces of Voldemort.

One possible plotline could be Harry being secretly trained by an unknown figure to become an assassin against the dark forces. He would have to hide this new identity from his friends at Hogwarts.

A plotline could involve an Eldrazi being brought to Hogwarts by a dark wizard who wants to use its power for evil. The students then have to work together to contain it. Along the way, they learn about the Eldrazi's nature and find that it's not entirely what they expected. There could be some interesting character development as they face this new and powerful threat.

One plotline could be Naruto being a transfer student at Hogwarts. He might struggle to adapt to the magic system while also showing off his ninja skills. Another could be Naruto teaming up with Harry Potter to fight a common enemy that threatens both the ninja world and the wizarding world.

One possible plotline could be that Harry, after some dark magic influence or a strange accident, starts to show Joker - like behavior at Hogwarts. He might play cruel pranks on his classmates and teachers, using his magic in unexpected and unethical ways.

One possible plotline is that Broly is brought to the Harry Potter world as a result of a powerful spell gone wrong. He initially causes chaos with his strength but then gradually learns about the concept of magic and starts to respect it. Another could be that Broly is a hidden protector of Hogwarts, his Saiyan powers being the ultimate defense against a new dark force that the normal magic in the wizarding world can't handle.

A possible plotline could be that Harry uses his invisibility to spy on Voldemort's followers and gather intelligence for the Order of the Phoenix. This would add an element of mystery and danger as he has to be extremely careful not to be detected.

Maybe Aragorn is summoned to Hogwarts by a powerful spell gone wrong. Once there, he has to figure out how to get back to Middle - earth while also getting involved in the magical world's problems. He could end up teaching the students about non - magical combat skills.