In a 'Harry Potter is a banker' fanfiction, the plot could center around Harry's new life as a banker. He might use his fame from defeating Voldemort to gain trust in the banking community. He could be faced with challenges like dealing with corrupt wizards who want to use the bank for illegal activities. He might also have to balance his new job with his old friends and the wizarding world's politics. Maybe he tries to create a new bank that is more inclusive for all magical beings, which causes a stir among the traditional banking families.
Well, it could be about Harry using his knowledge of magic to secure the wizarding banks. Maybe he discovers some new spells to protect the vaults from thieves.
A common plot twist is that the goblin banker is actually a spy for an underground magical resistance. He has been using his position in Gringotts to gather information. Harry Potter discovers this by accident and has to decide whether to trust him or turn him in. This adds a lot of suspense and moral dilemma to the story.
I'm not sure of a specific 'Harry Potter is a banker' fanfiction off the top of my head. However, you could also try joining Harry Potter fan groups on social media platforms. People there often share interesting fanfictions, and someone might know of one where Harry is a banker.
Some fanfictions could focus on the goblin banker's backstory. For example, how he came to work in Gringotts, his family's influence on his career choice, and his relationship with other goblins. Harry Potter could then interact with him in a way that changes both of their views on the wizard - goblin relationship in general.
The plot could involve a situation where a new form of dark magic is unleashed in the wizarding world, which spreads like wildfire and causes destruction similar to 911. The Ministry of Magic is caught off - guard. Hermione, with her vast knowledge, starts researching a way to counter this magic. Meanwhile, Ron and Harry lead the effort to protect the civilians. They set up shelters in places like the Room of Requirement and use Patronuses to guide people to safety. As they dig deeper, they discover that this dark magic was a planned attack by a long - hidden dark wizard group who wants to take over the wizarding world.
One interesting 'Harry Potter Banker Fanfic' could be about a wizard banker who discovers a long - lost magical account that has ties to an ancient prophecy. He then has to protect the account from dark wizards who want to use it for evil purposes.
One possible plot could involve a group of spiders that have been enchanted by a dark wizard. These spiders start attacking Hogwarts students. Harry, along with his friends Hermione and Ron, would need to find the source of the enchantment and break it to save the school. They might have to explore the Forbidden Forest more deeply and face their fear of spiders to do so. This would combine the elements of adventure, mystery, and the existing spider lore from the Harry Potter series.
The plot could involve Catwoman being drawn into the wizarding world by some mysterious magical force. She might start out as an outsider, trying to figure out how things work. Maybe she gets involved in a plot to steal a powerful magical object, but along the way, she starts to have a change of heart and decides to help the good guys instead.
A plot could be that Gaster has a connection to the Forbidden Forest in Harry Potter. He might be the source of some of the strange and dangerous creatures there. As Harry and his friends explore the forest more, they start to notice Gaster's influence. Gaster could also be using the forest as a way to try and get back to his own world or to gain power in the Harry Potter universe. This would lead to a series of adventures and battles as the characters try to either stop Gaster or understand his motives.
In this fanfiction, the plot could center around Harry Potter arriving in Tamriel during a time of great unrest. He discovers that there are parallels between the magical hierarchies in Tamriel and Hogwarts. He could get involved in the political struggles of the various factions in Tamriel while also trying to find a way back home. Along the way, he might teach some of the Tamriel mages about some of the more advanced magic he learned at Hogwarts, like Patronus Charms, and in return, learn about Tamriel's unique magical artifacts and how to use them.
One possible plot could be that Harry discovers that the wizarding world was actually created by androids in the far future as a sort of historical experiment. So he has to use his magic skills to break free from the control of these androids who are now trying to manipulate the wizarding world for their own purposes.