The plot could start with Harry making a firm decision to leave. He might go into hiding in the Muggle world, changing his appearance and identity. Then, the wizarding world would gradually realize his absence and start to search for him, which could lead to a cat - and - mouse chase.
One possible reason could be the trauma he has faced. Harry has endured a great deal of pain, from the loss of his parents to the constant battles and threats in the wizarding world. He might want to escape all that and find peace away from it.
One possible reason could be that in some fanfics, the author wants to explore a different side of Harry. Maybe he's tired of the constant chaos and danger in the wizarding world. Another reason might be to show his independence from the typical wizarding narrative. He could be seeking a more normal life away from all the magic and politics.
Matilda's character might become more confident in a wizarding environment. With all the new magic to learn and the challenges it brings, she would grow. For example, she could start out shy about using magic wands as it's new to her, but as she practices, she'd gain confidence.
The wizarding world would be in chaos. They would realize too late that they had pinned all their hopes on Harry and neglected him. There would be a great sense of guilt and despair. The Hogwarts students would be shocked and many would feel a deep sense of loss. The teachers might question their own actions and inactions that led to this. The Order of the Phoenix would be in disarray, having lost their main weapon against Voldemort.
It could be that in the fanfic, Harry Potter discovers some deep - seated secrets about the wizarding world's power structure. Feeling betrayed, he decides to take extreme actions to expose and destroy it. For example, if he finds out that the Ministry of Magic has been using unethical means to control the wizarding population, he might use his influence and magic to bring it all crashing down. He could start by revealing the truth to the public, which could lead to chaos and the destruction of the established order in the wizarding world.
It can create a sense of mystery. The wizarding world without Harry is a big change, and other characters have to deal with new situations. It might lead to new alliances and power struggles.
It could be about Harry Potter achieving ultimate power and ruling the wizarding world. Maybe he overcomes new and even more dangerous dark forces and in the process, he becomes the king. He could make new laws and bring about great changes to Hogwarts and the entire wizarding community.
The wizarding world would have a complex reaction. On one hand, many would support Harry as they believe he can bring positive change. On the other hand, there would be political factions within the wizarding world. Some might try to use Harry's new position for their own gain, while others would be cautious and want to maintain the status quo. Harry would have to navigate these different reactions and interests to ensure the stability of both the wizarding and non - wizarding parts of England.
Well, Umbridge is not one to tolerate things that go against her idea of order. If she reads fanfic, she could potentially use it as a means to further her control in the fanfic - created wizarding world. For instance, she might see a fanfic that portrays Hogwarts in a different way than she likes and then try to change it back to what she thinks is right. This could lead to a lot of conflict between her and the fanfic creators, as well as the characters within the fanfics who might oppose her actions.
A 'Harry Potter World Traveler' fanfic can expand the wizarding world in multiple ways. Firstly, it can introduce new magical locations. Instead of just Hogwarts and Diagon Alley, we get to see enchanted cities in South America or hidden islands in the Pacific. Secondly, it can explore different forms of magic. There could be a type of magic based on music in some far - off land. And thirdly, it can bring in new characters from various parts of the world, each with their own backstories and motives.