Another theme is the idea of power. Both Harry Potter (even as a female version) has her own magical powers, and T'Challa has the power of the Black Panther and the leadership of Wakanda. Fanfictions might explore how they use their powers together, or how their different understandings of power can either clash or complement each other. For example, in some fanfictions, they use their combined powers to face a greater threat that neither could handle alone.
There's also 'A Meeting of Worlds' which delves into how fem Harry Potter's magic would interact with the advanced technology of Wakanda under T'Challa's leadership. It's a fascinating exploration of two very different fictional universes colliding in a harmonious way. The character development in this fanfiction is quite well - done as they learn from each other's cultures and powers.
In Harry Potter and T'Challa fanfiction, one could imagine T'Challa as a wizard attending Hogwarts. Maybe he'd bring his Wakandan knowledge of magic and technology, which is different from the traditional magic in the Harry Potter universe. He could form an interesting friendship with Harry, Hermione, and Ron, sharing his unique perspective on power and responsibility.
Maybe it starts with fem Harry accidentally ending up in Wakanda. She and T'Challa initially clash due to their different cultures and ways of doing things. But as they get to know each other, they discover a deep connection and start to fall in love. Along the way, they have to deal with opposition from some in Wakanda who are skeptical of an outsider being so close to their king.
Well, T'Challa could teach the Hogwarts students about Wakandan self - defense techniques. This would be a new and exciting addition to their curriculum. Maybe he'd even start a new club for it.
I'm not sure if there is specific 'Harry Potter T'Challa Yaoi Fanfiction' out there. These are two very different fictional universes and combining them in a yaoi (male - male relationship) fanfiction is rather unusual. You might have to search on some very niche fanfiction websites or communities dedicated to such crossovers.
There are many fanfiction platforms where you might find such stories. Try Archive of Our Own (AO3). Just go to the site and use the search bar to type in 'fem harry is the mate of t'challa'. It has a vast collection of fanfictions, and you're likely to discover some great reads there.
One challenge is the different settings. Harry Potter has a magical, mostly European - influenced world, while T'Challa's Wakanda is a technologically advanced African nation. Blending these two distinct settings into a coherent story is difficult. Another is the character development. The two characters have their own backstories and personalities from their original stories. Making them fit into a yaoi relationship while still being true to their original selves is a big task.
Some common themes could be alternate universes where Tony and T'Challa have different genders. It might also explore their relationship in a new light, perhaps a romantic or a strong friendship dynamic. Another theme could be how their changed genders affect their roles within the Marvel universe, like how Fem Tony might approach technology differently or Fem T'Challa might lead Wakanda in a unique way.
One common theme is cultural exchange. Since Bucky comes from a different background compared to T'Challa and Wakanda. Their interactions often involve learning about each other's cultures. For example, Bucky might be introduced to Wakandan technology and traditions, while T'Challa learns about the modern world through Bucky.