Perhaps there could be a plot where Sirius and Harry team up to uncover secrets about the Dark Arts that are hidden in the Black family home. As they explore the old rooms and artifacts, they might stumble upon a powerful and dangerous object that the Death Eaters are also after. This would lead to a race against time to either destroy or protect the object while also fending off the Death Eaters.
Their relationship would likely become very close. Harry, who has always longed for a family, would finally have someone who truly cares about him like family. Sirius, on the other hand, would get to be the father - figure Harry needs. They would probably have a lot of heart - to - heart talks, sharing their joys and sorrows.
A big theme is the discovery of self - reliance. Harry, who is used to having some support at Hogwarts, now has to rely on his own instincts and Sirius' guidance. Also, the theme of secrecy plays a part. They need to keep their presence on the streets a secret from certain people in the wizarding world who might try to use their situation against them. This adds an element of mystery and danger to the story.
One reason could be Harry's impulsiveness. Harry often jumps into dangerous situations without thinking, and Sirius, being his godfather and having a protective nature, would shout at him to make him realize the risks. For instance, if Harry decides to go after a Death Eater alone.
Yes, there might be such fanfictions out there. Fanfiction writers often come up with creative and sometimes out - of - the - box ideas. They might explore the idea of Harry having a different relationship to Sirius in an alternate universe where he could be seen as Sirius's daughter. However, it's not a common or traditional take on the Harry Potter universe.
The 'Harry Potter' books are set in a magical world full of its own stories, prophecies, and secrets. Sirius is a complex character with a lot on his plate. He has to deal with his family history, his time in Azkaban, and his loyalty to his friends. Fanfiction is a form of creative writing by fans outside the original story. Sirius doesn't have the time or the inclination within the context of the story to be reading fanfiction. His life is too filled with real magical drama and danger.
Sirius could help Harry cope by sharing his own experiences of being an outcast in his family. He could tell Harry that just because his parents did this horrible thing, it doesn't mean he's unlovable. Sirius could also introduce Harry to his friends in the wizarding world, like Remus, who could also offer support and friendship.
It's possible that in the cave, they start to see each other as equals rather than just a mentor - student relationship. They might argue about the best way to deal with the cave's mysteries at first, but through that process, they learn to value each other's perspectives. Also, if one of them gets injured in the cave, the care and concern shown by the other would enhance their relationship.
The relationship could become strained. Sirius might start to view Harry differently, with a bit of wariness. He might not trust Harry as much as before in terms of making good decisions. But it could also lead to a more open relationship where they talk about things they previously avoided, like relationships and feelings.