It's also likely that they go to Romania. Given Sirius' knowledge of the wizarding world, he might know of a safe haven there. In Romania, they could be around dragons and learn about dragon - related magic. Harry would surely be fascinated by the dragons and it could be a place where he can grow stronger in a different kind of magical environment.
Perhaps they would head to America. In the wizarding world of America, there are different magical institutions and a large expanse of land where they could start anew. They might be drawn to the Ilvermorny School of Witchcraft and Wizardry area, to interact with new wizards and witches and learn from a different magical education system. Also, the American magical community might not be as involved in the affairs of the English wizarding world, providing them with some anonymity.
In the fanfic, Sirius and Harry leaving England could lead them to a hidden magical island. There, Harry could learn different kinds of magic that are not taught at Hogwarts. Sirius would be able to protect Harry better as they are far away from the threats in England. They might also start a new life where Harry can grow up without the constant fear of Voldemort's followers finding him.
One challenge could be transportation. If they are trying to leave secretly, they can't just use the regular wizarding transportation like the Hogwarts Express or Portkeys that are easily monitored. They might have to find some unregulated or hidden means of travel, like an old, enchanted flying vehicle that is difficult to control but less likely to be traced.
A possible plotline could be that they are on the run from the Ministry of Magic. Sirius knows some secrets about Harry's past that make it dangerous for them to stay in England. So, they head to a far - off magical land where they try to start a new life in hiding.
Their relationship would be severely damaged. Harry would likely feel betrayed by Sirius. After all, Sirius is supposed to be one of his protectors. It would be a huge breach of trust. Sirius, on the other hand, would probably be filled with guilt if he realizes his mistake. He would have to work hard to regain Harry's trust, if that's even possible in the context of the fanfic.
Sirius would probably be shocked at first. Then, he'd likely feel a deep sense of sadness and guilt. He might think that he should have been there more to protect Harry from getting those scars.
One possible reason could be that Sirius, being Harry's godfather, feels it's his right and duty to protect Harry. He might not trust Hagrid fully to keep Harry safe, especially considering the dangerous situation Harry is in. Sirius has a strong connection to Harry and wants to be directly involved in his upbringing and protection.
Well, if Sirius takes Harry to Voldemort in a fanfic, it would be a huge deviation from the normal story. One possibility is that Sirius is trying to make some sort of deal with Voldemort to save others. But Voldemort is not one to be trusted. Harry, being the Boy Who Lived, is a valuable asset to Voldemort for his own dark purposes. It could lead to a tense stand - off where Harry has to use his own wits and magic, even at such a young age, to try and escape the clutches of the Dark Lord.
The relationship could also take a more complex turn. Other characters might get involved in their conflict. Some might side with Sirius, thinking Harry was in the wrong, while others might try to mediate. This outside influence could either help or hinder the mending of their relationship, depending on how it's handled in the fanfic.
Yes, there are some fanfictions with this concept. In the Harry Potter fandom, writers often explore alternative family relationships through fanfics. This particular idea of Sirius being Harry's dad can lead to some interesting storylines, like re - imagining how Harry's upbringing would have been different if Sirius had been his father from the start.