The most interesting part might be how it changes the mystery and danger around Harry. In the original, Voldemort's target on Harry was due to the prophecy. But in this fanfiction, it could be a combination of that and her connection to Sirius. Also, it could change the role of the Marauders. James Potter was Harry's father in the original, but here Sirius takes that role. So how the memories and influence of the Marauders play out would be fascinating. And of course, the way Harry discovers her true identity and how she copes with it could be a really engaging part of the fanfiction.
One interesting aspect is the changed family dynamic. Instead of being an orphan with the Dursleys, Harry would have a different kind of upbringing with Sirius as her father. This could mean she has a stronger connection to the wizarding world from the start. Another aspect is how it would affect her relationships at Hogwarts. Her friends might view her differently, and her enemies too. Also, Sirius's knowledge and skills could be passed on to her in a more direct way, like advanced magic training or knowledge of the wizarding underworld.
There probably is. The Harry Potter fandom is huge and full of diverse ideas. Writers might explore this idea to add new twists to the story, like how Harry's relationship with Sirius would be re - imagined if he were his daughter, and how it would change the overall plot dynamics.
One interesting aspect is the exploration of Sirius's backstory. Fanfictions can dig deeper into his time at Hogwarts as a student, his friendship with James Potter, and how that influenced his relationship with Harry. For example, stories might show how Sirius's rebellious nature as a student translated into his actions as an adult when it came to protecting Harry.
One interesting fanfiction could be where Harry and Sirius Black's daughter team up to solve a mystery at Hogwarts that the adults are overlooking. They might discover a hidden chamber or a secret about a forgotten spell.
One interesting fanfiction could be about Sirius Black's daughter joining Harry Potter and his friends on their adventures at Hogwarts. She might inherit her father's brave and rebellious spirit, causing some interesting twists in the story.
One possible fanfiction could be about Sirius Black's daughter discovering her father's true nature and his relationship with Harry Potter. She might start at Hogwarts and face some challenges due to her father's reputation. For example, some students might be wary of her at first, but she gradually proves herself to be a brave and kind witch, just like her father.
Perhaps Sirius Black's daughter has a special connection to Harry through a long - forgotten prophecy. They start to notice strange coincidences and shared dreams. As they investigate, they find out that their destinies are intertwined in a way that could change the wizarding world. It could involve a journey to find a lost magical artifact that holds the key to fulfilling the prophecy.
She could also be an innovator. She might come up with new spells or magical techniques. Since she has the blood of Sirius Black in her, she could be a natural at magic and use her creativity to solve problems that Harry and his friends face, like finding a new way to combat the Dementors or a more effective way to pass their exams without the use of cheating spells.
One possible plot could be that Harry discovers the truth about her real parentage early on. She then has to deal with the implications of being Sirius' daughter while still at Hogwarts, facing both the admiration and suspicion from others.
One common plotline is Sirius Black escaping from Azkaban earlier and secretly training Harry in advanced magic. Another could be Sirius and Harry going on a hidden adventure to uncover more about Harry's parents. There are also stories where Sirius plays a more active role in the fight against Voldemort at Hogwarts, using his knowledge of the Dark Arts and his Animagus form to their advantage.
One interesting fanfiction could be about Sirius Black mentoring Harry Potter in some advanced magic that Dumbledore didn't teach him. It might involve Sirius sharing secrets of the Black family's magical heritage with Harry.