A lot of fanfictions play around with the Dursleys' relationship with Harry. They could be depicted as having a sort of begrudging respect for Harry. For instance, when Harry starts to show real courage and power, the Dursleys might start to see him in a new light. This is different from the original story where they mostly just try to suppress Harry. Also, some fanfictions might give the Dursleys magical abilities of their own, which completely changes their dynamic with Harry and the wizarding world.
In the 'the dursleys abuse harry fanfiction', the abuse can be multi - faceted. Physically, Harry could be pushed around or hit by Vernon. Emotionally, Petunia might constantly compare him unfavorably to Dudley, which is really damaging to Harry's self - esteem. And socially, they might prevent him from having any friends over, making him feel completely alone in the world.
The Board of Governors could also be portrayed as more hands - on in fanfiction. They might be actively involved in the day - to - day running of Hogwarts, not just making big - picture decisions. For example, they could be the ones to directly handle student discipline cases instead of leaving it all to the professors and the headmaster.
It might show their fear in a more extreme way. Instead of just being dismissive of magic, they could be absolutely terrified of it. For example, every time Harry does something even slightly magical, they could cower in a corner.
In the original series, Hedwig is mainly a faithful owl companion. But in fanfiction, she can be much more. She could be a magical entity with her own backstory and motives. For instance, some fanfictions might explore her origin in more detail, like she was bred from a special line of owls with unique abilities.
The Dursleys could also cripple Harry emotionally in fanfiction. Their constant belittling, isolating him from others, and treating him like a burden could break his spirit. This emotional crippling might make it difficult for Harry to trust people, form relationships, or even fully embrace his wizarding identity. He may become withdrawn and lack the confidence needed to face the challenges in the wizarding world.
Some fanfictions might depict the Dursleys as having a more complex relationship with Harry. They could be in a situation where they have to protect Harry from a greater threat, which makes them put aside their differences. For example, a dark wizard could be targeting Harry, and the Dursleys realize that their home is the safest place for him at the moment, so they have to work together with Harry to keep him safe.
It might show the constant power struggle between them. Harry, as a wizard, has an inner strength that the Dursleys try to suppress with their mundane and cruel ways. So it's a battle of wills.
Often, a good Dursley in fanfiction is the result of a different backstory. Maybe Petunia has a moment of reflection about her sister Lily and decides to treat Harry better. Vernon could also come around when he sees the power and influence that Harry might have one day and wants to be on his good side. So, in these fanfictions, they become more likeable and positive characters.
One way the Dursleys can be good in fanfiction is if they are forced to face the consequences of their actions early on. For instance, they might receive a warning from the wizarding world that if they don't treat Harry well, there will be serious repercussions. So they start to be nicer to him. They could provide him with a proper room, better food, and allow him to have friends over.
In some Harry Potter fanfictions, the Dursleys are depicted as nice. This could be a really interesting take. It might show how they could have been different if they hadn't been so influenced by their dislike for magic. Maybe they could have supported Harry more, or at least been less cruel. For example, a fanfiction could explore a scenario where Vernon Dursleys actually encourages Harry's academic achievements at school, instead of always putting him down.