Perhaps in the fanfic, the boggart - Vernon, starts to transform into different forms of abuse that Harry endured while living with the Dursleys. It could be a way for Harry to finally overcome his fear by using powerful magic that he has learned at Hogwarts. He might realize that the Vernon in his head is no longer as terrifying as the real Vernon was because he has grown stronger.
One possible plot could be that Harry has to face his fear of Vernon in a very public and unexpected way. Maybe during a school event at Hogwarts, the boggart appears as Vernon and starts to humiliate Harry in front of his friends and classmates. This would force Harry to confront his past traumas related to living with the Dursleys and Vernon's cruel treatment of him.
In this fanfic, the boggart being Vernon could also lead to some self - discovery for Harry. He might find out that his fear of Vernon is not just about the physical and mental abuse he suffered, but also about the feeling of being unwanted. This could then prompt him to seek out more about his own family history and find a sense of belonging that he never had with the Dursleys.
Another way Harry could deal with it is by surrounding himself with his friends. His friends could offer their support and encouragement. Together, they could create a sort of protective shield around Harry, making the boggart - Vernon less intimidating. Harry would then realize that he is not alone in facing his fears and that he has a support system that the real - life Harry didn't have when he was living with the Dursleys.
Perhaps Vernon Dursley sells Harry fanfic to get back at the wizarding world that he despises. He might think that by spreading false or embarrassing stories about Harry in fanfic form, he can somehow undermine the reputation of wizards. For example, he could write fanfics where Harry is shown as a bumbling fool, completely different from the real heroic Harry. However, this backfires as the wizarding world sees it as a comical attempt by a Muggle and it actually makes Harry more popular as they rally around to defend him.
One possible plot could be that Harry, through some magical mishap, is transformed into a small animal and Vernon, instead of being his usual cruel self, finds himself oddly attached to this new form of Harry. He might start to protect Harry from other threats in the wizarding world, not fully understanding what he's gotten into but feeling a sense of responsibility.
One possible plot could be that Harry shows a special talent early on that Vernon and Petunia recognize as something extraordinary. This makes them see Harry not as a burden but as a valuable part of the family. They then start to love and protect him, and this changes Harry's life completely. He no longer has to endure the abuse and neglect he faced in the original story.
Well, perhaps Vernon might beat Harry out of his extreme dislike for magic. He could be enraged by some accidental magic Harry does at home and lose his temper completely.
One possible storyline could be Harry facing his fear of his uncle in a more in - depth way. Maybe he has to confront his uncle in a magical setting within the fanfiction, like in a dream - like realm where his boggart - uncle taunts him with his past memories of mistreatment. This could lead to Harry finding new ways to overcome this fear, perhaps by using a new spell he discovers.
Maybe Vernon is jealous of Harry's magical abilities. He might see Harry as a threat to his 'normal' family image. Also, Vernon has always been a bully at heart and Harry, being an easy target in his house, becomes the victim of his pent - up anger.
It could be a story full of surprises. The Boggart might take on forms related to the FMA world, like the homunculi, which would be really strange for the Harry Potter characters. And for EDS, Edward might have to figure out how to use his alchemy without drawing too much attention in the wizarding world. He could end up using it in a very discreet way to defeat the Boggart. For example, he might transmute a small object in his pocket into a tool to scare the Boggart away.
In this fanfic, Vernon might be driven by his hatred for Harry and sees the baby as an extension of that. It could lead to a tense and dangerous situation for the baby and Harry's attempts to protect it.
This is a very disturbing and inappropriate topic. Fanfic should not involve such non - consensual and immoral content. There are many positive and ethical fanfics in the Harry Potter fandom that focus on friendship, adventure, and character growth.