What are the possible reasons for Sirius Black being Harry's father in fanfiction?

One reason could be the strong bond between them in the original story. Fanfic writers might think that making them father - son would enhance that bond further. Also, Sirius was a very important figure in Harry's life, so it makes for an interesting twist.

One possible reason could be miscommunication. Maybe Harry does something that Sirius misinterprets as a betrayal or a stupid mistake, leading to Sirius lashing out.

One possible reason could be a misunderstanding. Maybe some false information was spread about Harry that made Sirius believe he had done something unforgivable. For example, if there were rumors that Harry was involved with dark magic in some way, Sirius, who has a strong aversion to the dark side, might be quick to disown him.

Yes, in some fanfictions, Sirius Black is written as Harry's father. Fanfiction allows for creative reinterpretations of the original story, and this is one such interesting take.

In some fanfictions, it could be due to dark magic influence. A spell or a dark force might have corrupted Sirius's mind, making him turn against Harry.

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.

One possible reason could be differences in their approach to fighting Voldemort. Sirius might be more reckless and Harry, having faced more direct threats, could be more cautious. Another reason could be Sirius' over - protectiveness of Harry. He might try to stop Harry from taking certain risks, which Harry sees as necessary for his growth and the defeat of the Dark Lord.

Some fanfiction writers might make Sirius Black a Death Eater to explore the idea of redemption in a different way. If he starts as a Death Eater, then his journey to the side of good could be a more complex and interesting story. Also, it could be a way to add more mystery to the 'Harry Potter' universe by changing the nature of a familiar character.

In some fanfictions, Sirius Black can be depicted as Harry Potter's father. Fanfiction often takes creative liberties with the original story, so it's not uncommon to see such radical changes in character relationships for the sake of exploring new storylines or emotional arcs.

Well, in such a fanfiction, it could be due to a combination of factors. His isolation in Grimmauld Place might have taken a huge toll on his mental state. He might have felt like a burden to his friends, especially Harry. And the lack of any real future prospects, given his fugitive status and the ongoing battle against Voldemort, could have pushed him over the edge into taking his own life.