Perhaps in the fanfiction, Sirius has been influenced by some dark magic or a curse that makes him feel hatred towards his daughter. It could also be that he discovers a secret about her origin that he finds unacceptable, like she was fathered by an enemy in some way. However, these are all very dark and complex reasons that go against his original character traits.
In fanfiction, such a plot might seem very out of character for Sirius Black. In the original series, Sirius is a loving and loyal character. This could be a very dark and angsty take in the fanfic. Maybe the writer wants to explore complex family dynamics or some kind of tragic backstory that led to this situation. However, it goes against the general perception of Sirius as a heroic and loving figure.
One possible plotline could be that Sirius Black has been away for a long time, perhaps in Azkaban or on the run. When he finally meets his daughter, there is an initial awkwardness. But as time passes, he starts to bond with her over shared magical abilities. For example, he might teach her how to transform into her Animagus form if she has the potential for it. They could also bond over stories of his time at Hogwarts with the Marauders.
Well, if Sirius Black hates Harry Potter fanfiction, it could lead to a divide among fans. Some fans might respect his view and be more critical of fanfiction themselves, while others might disregard his feelings. Also, it could potentially limit the creativity within the fan community as people might be afraid to create content that could be seen as disrespectful to Sirius Black's character.
One reason could be the clash of cultures. Naruto is set in a feudal Japanese - inspired world with its own unique culture, while Aphrodite is from Greek mythology. The two cultures are very different, and combining them in fanfiction might feel jarring and not in line with the essence of Naruto.
It might be because of their moral values. Devils are often associated with evil and chaos in fictional stories. Naruto, who stands for good and order, would dislike them due to this fundamental difference. For instance, if devils in the fanfiction are shown to cause destruction and harm without any remorse, Naruto would surely hate them.
Naruto might dislike fanfiction because it can be a source of misinformation. Fans who read fanfiction might get the wrong idea about him or his world. He wants people to understand his story as it was originally intended. The original Naruto story is a carefully crafted narrative about ninja life, dreams, and the pursuit of peace. Fanfiction can deviate from this and make it seem like something else entirely, which he would find unacceptable.
In some fanfictions, the mother could be a character that was only briefly mentioned in the original series. For example, it could be a witch he knew from his school days at Hogwarts. They reconnected later in life and had a daughter. Or, it could be a new character who has a special connection to the Black family, perhaps a distant relative who got closer to Sirius and they had a child together.
The plot could involve the daughter growing up in the wizarding world, facing the challenges of her father's reputation. Maybe she's trying to clear his name while also learning magic at Hogwarts. She could discover some hidden secrets about her father's past and use that knowledge to make a difference in the wizarding community.
One possible reason is a misunderstanding. If there are rumors or false memories planted in Naruto's mind, he might believe his mom did something unforgivable. For instance, if he's made to think she was involved in the death of someone he cared about.
In such fanfiction, it could add a new dynamic to the story. Maybe she inherits some of Sirius' traits and faces her own adventures in the wizarding world.