Well, in some fanfictions, Harry might control the Dursleys by making them understand the wizarding world. He could show them magical things and, as a result, they start to respect him and his abilities. This could lead to a whole new dynamic in the household, where the Dursleys are no longer mean but rather in awe of Harry and his magic.
In 'harry controls the dursleys fanfiction', a common plotline is Harry using mind - control magic on the Dursleys. He could do this to prevent them from treating him badly or to make them do things that are beneficial for him. For instance, he might make them enroll him in a better school or allow him to have more freedom. This can also lead to a change in the Dursleys' attitude towards magic in general, as they are now under Harry's control and have to adapt to his magical world.
One possible plotline could be that the Dursleys start to show their love by secretly protecting Harry from the wizarding world's threats. Maybe they learn about a dark wizard targeting Harry and use their Muggle ways to keep him safe without him even realizing it.
One possible plotline could be Harry using his newly discovered magical abilities in unexpected ways against the Dursleys. For example, he might make the Dursleys' dinner plates fly around when they are being particularly mean to him.
One interesting plotline could be Harry showing early signs of magic that the Dursleys try to suppress. For example, he might accidentally make Dudley's toys float when he's angry or frustrated.
One possible plotline could be Harry finding a new family among the magical creatures. For example, he might be taken in by a friendly centaur herd who teach him their ways of magic and survival. Another could be Harry being found by a secret group of wizards who are against the Dursleys' cruel treatment and they help him develop his magic in a more positive and nurturing environment. And there could also be a plot where Harry discovers a hidden magical power within himself as a result of the abandonment, like the ability to communicate with the spirits of Hogwarts, which then guides him on a new path to face Voldemort.
In certain fanfictions of this type, Harry could be found by a powerful but reclusive wizard. This wizard decides to mentor Harry in the ways of ancient and lost magics. Harry then uses this knowledge to not only become a very powerful wizard but also to change the wizarding world's view on things like blood purity. He may also go on a journey to find out why the Dursleys abandoned him and in the process, uncover some dark secrets about his family that had been long buried.
Another plotline might involve Harry making friends outside of Hogwarts who help him deal with the abuse at home. These friends could be from the wizarding community or even muggles with special abilities. They could work together to expose the Dursleys' behavior to the wizarding world, leading to Harry being removed from their care.
Well, in some fanfictions, Harry discovers he can control the elements as a result of some ancient magic. He then uses this power to create new spells. He might combine fire and air to make a super - hot blast of wind that can melt metal doors in a dungeon where a dangerous creature is locked. Or he could use water to form ice bridges across a dangerous chasm in the Forbidden Forest.
One possible plotline could be Harry discovering a hidden magical ability that helps him escape. For example, he might find out he can teleport short distances, which he uses to get away from the Dursleys' house when they are being particularly cruel. Another could be that he gets help from an unexpected magical creature that has been secretly observing him all along. Maybe a house - elf that takes pity on him and shows him a secret passage out of the house.
One possible plotline could be Harry finding a way to break free from the chains and use his magic to confront the Dursleys about their mistreatment. Another could be the Dursleys realizing the error of their ways after chaining Harry up and having a change of heart. Or perhaps there are magical forces at work that lead to a series of adventures while Harry is still chained, like dealing with strange creatures that are attracted to the situation.
Obviously, Harry Potter is one of the main characters. He is the one who has the power to control the Dursleys. And of course, the Dursleys - Vernon, Petunia and Dudley - are also main characters as they are the ones being controlled by Harry.