Perhaps Harry uses his influence among his friends. Hermione could help him find some loophole in the Muggle - wizarding laws regarding property. Ron might provide some comical support, like trying to use some half - baked spell to make the Dursleys uncomfortable enough to leave. In the end, Harry evicts them and takes over the house, turning it into a place that's more welcoming for himself and his wizarding friends when they visit the Muggle world.
In this fanfiction, Harry could have a change of heart after learning more about his parents' sacrifice. He realizes that he doesn't have to tolerate the Dursleys' abuse any longer. He starts to gather evidence of their mistreatment of him over the years. With the help of Dumbledore or some other wise wizard, he presents this evidence to the proper authorities in the wizarding world, who then order the Dursleys to vacate the premises. Harry then decides to either sell the house or keep it as a symbol of his new - found independence from his Muggle relatives.
Dumbledore might play a role. He could be the one who encourages Harry to stand up to the Dursleys. He might have some hidden knowledge about the relationship between the wizarding world and the Dursleys that could help Harry. Also, Hagrid could be involved. He could provide some muscle if things get physical. He might also offer some emotional support to Harry, as he's always been like a big, friendly giant to him.
Perhaps Harry sues the Dursleys for false imprisonment. He realizes that all those years of being confined to his room or the cupboard were illegal. He enlists the help of Hermione, who is well - read in both wizarding and Muggle laws. They present a strong case against the Dursleys. As a result, the Dursleys face public humiliation in their neighborhood, and Harry finally gets the justice he deserves, while also starting to heal from the trauma of his childhood.
One possible plot could be that the Dursleys, out of their long - held hatred and envy, finally find a way to use dark magic against Harry. Maybe they make a deal with some dark wizards who provide them with a powerful curse. They manage to cast it on Harry when he's at his weakest moment, perhaps during one of his vacations at Privet Drive.
In this fanfiction, perhaps the Dursleys' constant abuse and neglect cause Harry to have some sort of mental or physical disability. It might show how he has to overcome not only the challenges of the wizarding world but also the trauma inflicted by his Muggle relatives. For instance, he could have problems with his legs from being locked in a cupboard for long periods, which would be a physical crippling, and then have to deal with the self - doubt and fear that comes with it.
One possible plot could be that evidence of their abuse towards Harry finally surfaces. Maybe a wizarding neighbor who has been secretly observing them reports their cruel treatment of Harry to the wizarding authorities. Then they are arrested and sent to a wizarding jail, where they struggle to adapt to the magical world's justice system.
In this kind of fanfiction, perhaps Harry is rescued by the Order of the Phoenix earlier than in the original story. They might have realized the Dursleys' mistreatment sooner. Then Harry could start his magical training earlier, away from the hostile environment of the Dursleys' home. He may also form closer bonds with other members of the Order, like Sirius, who could play a more active role in his upbringing.
One possible plot could be that the Dursleys receive a threat from the wizarding world that they can only be protected from if Harry stays with them and helps. Harry, being a good - hearted person, decides to do so and in the process, he starts to understand them better and grows to love them.
Well, one possibility could be that the Dursleys suddenly realize Harry's importance and the power he holds. They might see how he could bring them some sort of status or protection in the wizarding world. So, they start to accept him, change their attitude towards him, and perhaps even help him in his magical studies in secret.
In some interpretations, it could be that Harry finally snaps after years of abuse from the Dursleys. Maybe they pushed him too far one day and in a fit of rage, he uses his magic to end their lives. It's a very dark and extreme take on the Harry Potter universe.
If Harry Potter died at the Dursleys, it would be a huge shock to the magical community. First, the Dursleys, who had always resented Harry, would suddenly find themselves in a very difficult situation. They were supposed to protect Harry, but his death would surely draw the attention of the Ministry of Magic. In fanfiction, this could lead to investigations into the Dursleys' treatment of Harry. Magically, the protection that Harry's mother's sacrifice provided might be broken in a different way. And Voldemort, unhindered by Harry, could start to reshape the wizarding world according to his dark desires much more quickly.