It could be about Sirius teaching Harry advanced magic skills like Patronus charm. Sirius, being a skilled wizard, might train Harry to be better at dueling and facing dark wizards.
Well, perhaps Sirius trains Harry in advanced defensive magic. Harry could learn spells like the Patronus charm more effectively under Sirius's tutelage. Sirius might also teach Harry about the wizarding world's secrets that Dumbledore didn't share.
Neville could be part of it too. Maybe he sees Harry's training and gets inspired to improve his own magical abilities. He could learn from Harry's experiences under Sirius's training. And the Weasley twins might show up to add some mischief and perhaps even create some magical gadgets to aid in Harry's training.
Well, it depends on what you consider 'good'. Some people might like the ones that focus on Harry's internal struggle while being trained by Grindelwald. For example, there could be fanfictions where Harry has to decide whether to follow Grindelwald's teachings or stick to his own values. However, not all such fanfictions are well - written. Some might have plot holes or out - of - character moments.
Well, 'harry is trained fanfiction' might revolve around Harry going through a training process. It could be in a Hogwarts - like setting if it's related to the Harry Potter universe. He could be trained by a mentor, perhaps Dumbledore or another powerful wizard. Or it could be a completely different take where he's trained in a non - magical skill but still within the fanfiction's unique plot and world - building.
There could be many different authors who write 'harry is trained fanfiction'. Fanfiction is a very open - ended and community - driven form of writing. It could be written by an amateur writer who is a huge fan of the original work (presumably something related to a character named Harry). They might write it just for fun or to explore a different side of the character that they feel wasn't explored enough in the original.
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.
Maybe Dumbledore. He often has mysterious ways of providing Harry with tools or companions to help him in his journey. The trained hawk could be one such strategic gift from Dumbledore.
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.