One idea could be that Harry grows up with cat - like reflexes and stealth. He might be able to move around Hogwarts unnoticed more easily, like a cat prowling in the shadows.
It could be that Harry has a special bond with magical cats in the wizarding world. These cats help him uncover secrets about his parents that normal wizards wouldn't know. They might lead him to hidden places or show him memories in a way that is unique to his upbringing. For instance, they could take him to a secret room where his parents left him a special heirloom or a powerful spellbook.
One interesting plot could be how Harry's magical abilities are perceived in a world of nations. Maybe he uses his magic to solve international disputes. Another idea is that different nations try to influence his upbringing, each adding their own cultural and magical elements to his training.
In the fanfiction, it could be interesting if Harry uses his magic to protect the other orphans from bullies. He might not fully understand his powers yet, but his instincts kick in. And then when he finally gets his Hogwarts letter, the other orphans are both sad to see him go but also excited for him, and he has to figure out how to leave the only home he's known while also being eager to enter the wizarding world.
One interesting plot idea could be that Snape, in raising Harry, teaches him advanced potions from a very young age. Harry becomes a prodigy in potions, much to the surprise of the other Hogwarts students. Another idea is that Snape's strict but fair upbringing makes Harry more reserved and less impulsive, which changes the way he interacts with his friends. He might be more cautious and calculating in his actions, especially when dealing with enemies like Voldemort.
One plot idea could be that Shield trains Harry in combat and espionage skills from a young age. This makes him a more physically and tactically adept wizard compared to the original story. He might use his new skills to uncover dark secrets within the wizarding world earlier.
Well, in a 'Harry Potter raised DC crossover fanfiction', perhaps Harry is raised by Wonder Woman. He could grow up learning about Amazonian values along with his own magical heritage. His magic might be seen as a new form of power in the DC world. For example, he could use magic to create protective shields during battles against the forces of Ares. Or he could be raised by the Flash, and use his magic to help the Flash with time - related problems, like creating a time - freezing spell to stop a time - traveling villain.
One idea could be that Harry grows up with a very different set of values. House elves are known for their loyalty and hard work. So, Harry might be more in tune with serving others selflessly. For example, he could be more eager to help his classmates with their problems without expecting anything in return.
One plot idea could be that Harry's grandparents are very strict about magic, so he has to secretly practice. Another could be that they are part of a secret wizarding society that has been in hiding, and Harry discovers their secrets. Or perhaps they have a special connection to Voldemort's past that Harry uncovers.
One plot idea could be that Harry discovers a hidden magic within the orphanage itself. Maybe there's a secret room that holds ancient spells or a connection to a long - forgotten wizarding family. Another idea is that the other orphans start to show signs of magic too, and Harry has to figure out how to protect them from the wrong kind of attention. Or perhaps the orphanage is under a curse, and Harry's presence there is the key to breaking it.
One idea could be that Harry, in his Animagus form from a young age, has a unique bond with the magical creatures in the Forbidden Forest. They protect him and he learns their ways, which gives him an edge when it comes to dealing with dark magic later on.
One interesting idea could be how Harry's personality might be different. Maybe he'd have a more unique set of skills or values influenced by Zat. Another aspect could be the relationships he forms. His friendships might take on different dynamics compared to the original story.