Voldemort's remaining followers could be the antagonists. Even though Voldemort is gone, there are still some Death Eaters who are bitter about their loss. They might see Harry leaving with Fleur as an opportunity to get revenge on Harry or to use Fleur as a hostage to gain power. They could try to ambush them on their journey, creating a lot of dangerous situations for Harry and Fleur.
It could be that they leave to attend a special magical training that is only available in a very secluded place. They might have received an invitation from a very powerful and reclusive wizard. This training could enhance their magical abilities in ways that Hogwarts or Beauxbatons couldn't. They see this as an opportunity to become stronger and more self - reliant, so they leave together, excited for the new challenges and knowledge that awaits them.
In some fanfictions, Fleur might leave Bill for Harry because she realizes that Harry has a certain selfless quality that she admires more. Harry's constant fight against evil and his willingness to sacrifice himself could be very appealing to Fleur. Also, it could be that the fanfiction is set in a situation where Bill is involved in something that Fleur morally opposes, and Harry represents a more morally upright choice for her.
It could cause a great deal of shock and gossip. The Weasley family, especially Bill's siblings, would likely be very angry and confused. There might be a rift between the Weasleys and Fleur, and perhaps even some tension between the Weasleys and Harry. After all, Bill is a well - liked member of the wizarding community.
There could be. Fanfiction is a vast world. Some authors might explore such a complex relationship shift in their stories. However, it might not be as common as more typical pairings in the Harry Potter fandom. You could also check fanfiction communities on Reddit or Tumblr for recommendations.
Often, Luna Lovegood can be found in such fanfictions. Her unique and dreamy nature could bring a different dynamic to the harem. Neville Longbottom might also be involved in some way, perhaps as a friend who supports the harem and helps them out in times of need. There could also be some foreign exchange students or magical creatures in human form that end up in the harem for various reasons.
In fan fiction, this could be a really interesting and complex plot. It might be exploring themes of love, loyalty, and unexpected relationships. Maybe the writer wants to show how emotions can be so unpredictable that even in a world like the one in the story, a situation where Bill leaves pregnant Harry for Fleur could occur. It could also be a way to create drama and tension among the characters and their relationships.
At first, their relationship might be a bit strained. Harry is used to his own space and friends, and Fleur has her own circle. But as they live together, they'll start to respect each other's differences. For example, Fleur might be more flamboyant in her magic use, while Harry is more practical. They'll start to see the value in each other's approaches and become closer friends.
Archive of Our Own (AO3) is a great place to start. It has a large collection of Harry Potter fanfiction, and you can use the search bar to look for stories with this specific plot. Just type in 'Fleur leaves Bill for Hermione' and see what comes up.
One possible reason could be that Fleur sees Harry as a powerful and important figure. In the wizarding world, Harry is the famous Boy Who Lived. Fleur might be possessive because she wants to be associated with his fame and power. Also, his bravery and skills could be attractive to her, making her want to have him all to herself in the fanfiction world.