The wizarding world would likely be in shock. Harry was seen as a hero, and this act would completely change their perception of him. Some might think he was finally getting revenge for all the abuse he endured, but many would condemn his actions as murder is still a serious crime in the wizarding world.
This type of fanfiction has significant ethical implications. It changes the fundamental nature of the relationship between Harry and the Dursleys. In the original, Harry overcomes the Dursleys' cruelty through his own strength and the support of his friends at Hogwarts. By having him murder them, it's a complete subversion of that positive arc. It also sets a bad example for younger fans who look up to Harry as a role model, making it seem like violence is an acceptable way to deal with those who wrong you.
One possible plot could be that Harry finally snaps after years of abuse from the Dursleys. He might discover some dark magic that he uses against them in a fit of rage. Maybe he finds out they were involved in something really evil that endangered his life all along, and that's what drives him to murder them.
Yes, there might be some out there. Some fanfictions that explore such a dark and extreme concept can be well - written in the sense that they might have a complex plot, in - depth character exploration, and good writing style. However, it goes against the general positive image of Harry Potter in the original series.
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.
It's possible. In some fanfictions, authors might explore complex motives for the Dursleys' actions. Maybe they could be under some dark magic influence that makes them act out of character and in a more extreme way. However, this goes against the general perception of the Dursleys in the original series, where they are mainly just cruel and neglectful without such extreme murderous intent.
One consequence could be that Harry becomes withdrawn. He's so used to the abuse that he doesn't trust people easily. He might have nightmares often, reliving the moments of abuse. For instance, if Vernon has hit him before, he could have flashbacks in his sleep.
Well, in fanfic, the Dursleys' abuse of Harry can be shown in different ways. They might isolate him from the outside world. For instance, not allowing him to have friends or participate in normal neighborhood activities. They could also starve him, giving him very little food while Dudley gets plenty. This kind of treatment is often explored in detail in fanfiction to show how harsh Harry's life is with the Dursleys.
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.