Well, perhaps Harry would start by making the Dursleys' house a bit of a chaos. He could make the stairs creak whenever Uncle Vernon is trying to sneak around, or make Aunt Petunia's precious china rattle whenever she is being particularly mean. He might also use magic to make Dudley's new clothes look like old rags in front of his friends, which would be quite embarrassing for him.
Maybe Harry uses magic to make their house a mess. He could turn Dudley's room into a pigsty or make Aunt Petunia's precious china float and then smash. It's his way of getting back at all the years of mistreatment.
Well, in this kind of fanfiction, Harry might meet some new magical creatures unique to Canada. Maybe he'll encounter a friendly Canadian werewolf who helps him hide from any threats sent by the Dursleys or Voldemort's followers.
Well, one possibility is that Draco would be completely out of his element at the Dursleys'. He's used to luxury and magic, while the Dursleys' house is a non - magical and rather dull place. He might start to understand Harry's pre - Hogwarts life better. For example, he could see how Harry was treated like an outcast, which might change his view of Harry. Maybe they'd bond over their shared dislike of the Dursleys' rules and behavior towards them.
In this fanfiction, Harry might grow up with a different personality. Maybe he'd be more meek at first, having been constantly put down by the Dursleys. He could have a hard time discovering his magic, as the Dursleys would surely try to hide it from him. For example, he might find strange things happening around him but be too afraid to tell anyone because of the Dursleys' strict control.
Obviously, Harry Potter himself is the main character as he is the one getting back at the Dursleys. The Dursleys - Uncle Vernon, Aunt Petunia, and Dudley - are also main characters as they are the targets of Harry's revenge.
One thing that could happen is that the wizarding world would be in chaos. The Death Eaters would be confused by Bellatrix's actions, and the Order of the Phoenix would be very suspicious. Harry would be in a difficult position, not knowing whether to trust Bellatrix or not.
Well, they might have a really awkward encounter. Ginny could be shocked by the Dursleys' rudeness towards Harry. And Harry would probably be super tense, trying to keep Ginny from getting too involved in the Dursleys' mean - spirited remarks. Maybe Ginny would stand up for Harry more than he's used to, which could lead to an unexpected turn in the relationship between the Dursleys and Harry.
In fanfiction, when Harry and Ginny meet the Dursleys, there could be a lot of tension. The Dursleys are not fond of anything related to magic. Ginny, being a confident witch, might stand up to the Dursleys' rudeness towards Harry. Harry, on the other hand, would be in an awkward position as he has to deal with his Muggle family and his magical girlfriend at the same time. There could be some humorous exchanges as Ginny tries to understand the strange Muggle world of the Dursleys while also showing them that magic is not something to be feared.
In the fanfiction, Gaara might gain new powers along with getting Shukaku back. Maybe he'll have better control over sand abilities, as Shukaku was a source of his power before. He could also use Shukaku's strength to protect his village more effectively.
Well, in such a fanfiction, Harry might end up in a different house than Gryffindor. He could be resorted into Slytherin, which would completely change his relationships. For example, his friendship with Ron and Hermione might be strained as they are in Gryffindor. And he'd have to deal with the Slytherin stereotype and make new friends among them.