In some 'Harry Potter raised differently' fanfictions, he could be raised by the Malfoys. This would lead to a very different Hogwarts experience for him. He might have a more Slytherin - influenced view of magic and the wizarding world.
Another idea could be Harry being raised by Sirius Black. He would grow up with a more rebellious and free - spirited attitude. Sirius would teach him about his parents in a more personal and passionate way compared to the Dursleys' neglect.
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.
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.
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 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.
When raised by Death Eaters in fanfiction, Harry's moral compass could be completely distorted. He might struggle with his identity, being torn between the good he was born with and the dark teachings he received. This would lead to a very complex and different plot as he tries to find his true self.
In this fanfiction, Harry's development would deviate a lot from the original. His sense of right and wrong would be blurred. Since he's raised by devils, he may not have the same values as the normal Harry. He could be more self - centered, focused on his own survival and power gain rather than the well - being of others. His magical abilities might also develop in a more unorthodox way. Instead of learning the traditional spells for good, he might learn spells that are more harmful or controlling.
He develops a more rebellious streak. In the original, Harry was quite respectful of authority in the wizarding world. But being raised by bikers, he might question rules more often. For example, he might not be as quick to follow Hogwarts' strict regulations.