One main theme is power. The Black Fire is often depicted as a very powerful force, and the characters must grapple with how to control or use it. Another theme is family legacy. Since it's related to the Black family, it explores how the family's past actions and secrets are intertwined with the Black Fire. Also, there's the theme of good vs evil, as the Black Fire can be used for both noble and nefarious purposes.
Most likely Harry Potter would be a main character, as the title implies. There could also be his friends like Hermione and Ron. And perhaps some new characters that are specifically related to the concept of the black fire, like an old wizard who teaches Harry about it.
Well, a main theme is often the exploration of the wizarding world from Daphne's perspective. Since the original books mainly follow Harry, fanfiction about Daphne in the Goblet of Fire can show different aspects of Hogwarts and the tournament. Another theme is loyalty. Daphne might have to decide where her loyalties lie, whether it's with her house, her friends, or something else. And then there's the theme of magic and its power. Daphne could be involved in situations that test her understanding and use of magic during the events of the Goblet of Fire.
In this fanfiction, the theme of transformation is prominent. Harry's life is transformed when he becomes the Black heir. He has to adapt to new expectations and a different social standing within the wizarding world. The theme of loyalty also comes into play. He has to decide which parts of the Black family he wants to align himself with and which values he will uphold. And finally, the theme of discovery is key. Harry is constantly uncovering new things about the Black family and his own place in it, which drives the story forward.
One main theme is family heritage. Since it involves the Black and Bones families, there's a lot of exploration of their lineages, their magical abilities passed down through generations, and the family secrets that come with that.
I'm not sure specifically as there could be many different takes in this fanfiction. It might be about Harry Potter having some special power or connection to black fire, perhaps using it in battles against dark wizards or in solving mysteries within the wizarding world.
One main theme is family loyalty and betrayal. In many Black family tree fanfictions, characters have to decide whether to stay true to their family's traditional values or break away for what they believe is right. For example, Sirius Black was a prime example of this in the original series, and fanfictions often expand on this idea within the context of the whole family tree.
Family is a major theme. The Black sisters come from a complex family background, and in these fanfictions, it's often explored how their family ties influence their actions. For example, Narcissa's loyalty to her family and how it might conflict with her feelings towards Harry.
One main theme is family. It shows a different family structure for Harry, with Sirius as his father. Another theme could be identity. Harry would have a different sense of self, being part of the Black family. And there's also the theme of loyalty, as Sirius would be even more fiercely loyal to his son in these stories.
Power would be a major theme. Since Harry is the 'black king', it implies a great deal of power and perhaps a different kind of leadership. Another theme could be identity, as Harry has this new role that is quite different from his traditional one.
Many black Harry Potter fanfictions explore the theme of heritage. If Harry is black, his connection to magic might be linked to different cultural heritages. It could be African - based magic or a blend of different magical cultures. This theme allows for a lot of creativity in exploring new types of magic and how they interact with the existing wizarding world.