The 'Fish out of Water' trope is often seen. Fem Harry, coming from a world that's not entirely centered around the sea gods, finds herself in a strange new situation when involved with Poseidon. Another is the 'Redemption' trope. Maybe Poseidon has some past deeds that he needs to atone for, and fem Harry plays a part in that. The 'Alliance' trope is also possible, where they form an alliance to face a common enemy, like other gods or dark forces.
A common trope could be the 'Power Discovery' trope. Fem Harry might discover she has some sort of connection to Poseidon's power, and as she explores this, she grows in strength. There's also the 'Underdog' trope. Despite being a female Harry, she might be underestimated at first, but with Poseidon's help, she rises above her challenges. And then there's the 'Mystery' trope. There could be a mystery surrounding her connection to Poseidon that she has to solve.
One popular trope is the 'Chosen One' aspect. In fem Harry's case, she could be chosen by Poseidon for a special quest. Another is the 'Mentor - Protégé' relationship, where Poseidon guides fem Harry in her journey, perhaps teaching her about her newfound powers related to the sea. Also, the 'Forbidden Love' trope can be used, as their different natures - a human - like fem Harry and a god like Poseidon - might make their relationship something that others oppose.
Well, there's the 'fish - out - of - water' trope. Since Fem Harry is likely not used to the royal life at first, she has to navigate through all the strange rules and etiquettes of the royal court. This can lead to some humorous situations. And then there's the 'royal conspiracy' trope. Maybe there are some nobles who don't want Fem Harry to claim her rightful place in the royalty, so they plot against her. It adds a lot of drama to the story.
One popular trope is the 'fish out of water' scenario. A fem Harry Potter in the realm of Hades would be quite out of place. She'd have to adapt to the dark and often unforgiving world of Hades. Another is the 'powerful outsider' trope. Given Harry's magical abilities, she'd be a force to be reckoned with in Hades' domain. And the 'romantic entanglement' trope is also common, perhaps a relationship between fem Harry and Hades or one of his minions, adding a layer of drama and passion to the story.
In Harry Potter fanfiction, a common trope with Fem Blaise is the 'hidden - power' trope. This means that she has some sort of hidden magical ability that is only revealed as the story progresses. It could be something related to ancient magic or a unique way of using spells. Also, the 'outsider - within - Slytherin' trope is quite popular. Despite being in Slytherin, she may not fit in completely because she has different values or beliefs. This can lead to her having to navigate complex social situations within her own house while also forming connections outside of it.
In fem Harry Potter and Sailor Moon fanfiction, a common trope is the friendship - building aspect. The characters from both series have to learn to trust and work together. This often involves some initial misunderstandings and then a deepening of their relationships. Also, the 'hidden identity' trope is quite popular. Maybe fem Harry has to keep her wizarding identity a secret in the Sailor Moon world or vice versa.
The 'unlikely allies' trope is often used. Given their very different backgrounds, fem Harry Potter and Bruce Banner make for an unlikely pair. But in fanfiction, they often end up working together towards a common goal. There's also the 'culture clash' trope as the magical and scientific cultures they come from are so different. This leads to some really interesting interactions and storylines.
A common trope is the 'romantic entanglement' trope. Writers often pair the fem Harry Potter with various characters from Game of Thrones. It could be with Jon Snow, creating a story of two outcasts coming together. Or she might be paired with Tyrion Lannister, leading to an interesting dynamic of a powerful magical being and a clever, but often underestimated, man. There's also the 'mentor - mentee' trope where she either mentors someone in Westeros about magic or is mentored by someone about the ways of Westeros.
One popular trope is the 'Changing the Future' trope. In many of these fanfictions, fem Harry travels back in time with the hope of changing Tom's path, so he doesn't become Voldemort. It adds a lot of drama and moral dilemmas as she tries to interfere without causing more chaos.
For fem Harry, her character can be developed by showing her struggle with her new identity in a world with Poseidon. She could start as a bit of a loner, but as she bonds with Poseidon, she becomes more confident. Poseidon, on the other hand, can be developed by showing his softer side. Maybe he starts as a very strict god, but as he gets to know fem Harry, he becomes more lenient and caring.
One popular trope is the 'Changing the Future' trope. In many of these fanfictions, fem Harry travels back in time with the intention of stopping Tom Riddle from becoming Voldemort. This trope allows for a lot of exploration of the 'what - ifs' in the Harry Potter universe.
One popular trope is the 'fish out of water' where fem Harry, coming from a magical world, is suddenly in a world with Susan Storm's super - scientific environment. Another could be the 'power - sharing' trope where they learn from each other's powers. For example, Harry might teach Susan some magical concepts related to energy manipulation, and Susan could show Harry how to better control and use her powers in a scientific way.