Harry is the central figure, but there might be a leader in Zeltech who plays a major role in the story. This leader could be a wise and powerful figure who sees something special in Harry. There could also be other young members of Zeltech who become Harry's friends or rivals as he adjusts to his new life.
Well, perhaps in this fanfiction, Zeltech could be a powerful wizarding family or organization. The plot might involve Harry being adopted by them due to some special circumstances, like they saw his great potential and wanted to protect him from the Dursleys. They could then train him in unique forms of magic that are different from what he would learn at Hogwarts.
One common theme is family. Since Harry is being adopted, the new family dynamics, love, and acceptance are often explored. For example, how he forms bonds with his new family members.
One great fanfiction could be 'The New Beginning' where fem Harry's life takes a magical turn after being adopted by Zatanna. It explores how Harry discovers her new powers and her relationship with Zatanna.
Ron could also be there. He might be a bit jealous at first if Harry's adopted family is wealthier or has more influence in the wizarding world. But later, he would support Harry as always.
The Weasleys are very common. Given their big hearted nature and their closeness to Harry in the original story, it makes sense for them to adopt him in fanfiction. They already treat him like family, so it's a natural fit.
Obviously, Harry Potter is one of the main characters as the story is about him being adopted. Sirius Black could also be a main character, as he is part of the Black family and might play a big role in Harry's new life.
In the 'Harry adopted by the Malfoys' fanfiction, one possibility is that Harry would receive a very different kind of magical education. The Malfoys might try to mold him into a Slytherin - like wizard, but Harry's own Gryffindor - like courage would constantly be at odds with that. Also, his relationship with Draco could be very complex, ranging from initial rivalry as they are brought up in the same household to a possible understanding and even friendship later on.
They're popular because they offer a fresh take on the well - known Harry Potter story. By changing his family situation through adoption, it can completely shift the dynamics of the story.
In such a fanfiction, Harry might be raised with a very different set of values. Voldemort could try to mold Harry into his own image, perhaps teaching him dark magic. But Harry might also secretly hold on to his own sense of good. For example, he could use the knowledge Voldemort gives him to ultimately turn against him.