In Harry Potter fanfic, boggart scenarios can be really creative. Consider a boggart that reflects a character's fear of failure. For example, Draco's boggart could be him failing to uphold his family's reputation. This would play into his insecurities. Then there could be a boggart that is related to a character's secret desires. Maybe Cho's boggart is Cedric coming back but not loving her anymore, which ties into her unresolved feelings about him. And for Seamus, his boggart might be not being able to perform magic at all, which is a fundamental part of his identity as a wizard.
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.
One possible scenario in this fanfiction could be that Harry Potter and Sasuke are somehow transported to a shared magical realm. When they encounter a Boggart, Harry might see Voldemort at first, given his past traumas. Sasuke, on the other hand, could see Itachi. But as they realize they are in this together, they combine their magical and ninja skills to defeat the Boggart. Maybe Harry uses a Patronus charm while Sasuke uses his Sharingan to disorient the Boggart.
One interesting 'Harry Potter Boggart' fanfiction could be one where Neville's boggart turns into something unexpected, like a happy Snape instead of his usual grandmother. It adds a unique twist to the character's fear and development.
Some 'Harry Potter Boggart' fanfics focus on how different Hogwarts houses might face boggarts. In Gryffindor, a common boggart could be seen as cowardice, but in one fanfic, a Gryffindor's boggart is actually the harm coming to their friends because they value friendship so much more than their own bravery.
A common boggart scenario in fanfiction is related to the characters' insecurities. For Harry, it could be that the boggart shows him as the cause of all his friends' misfortunes, emphasizing his fear of being a burden or a danger to those he loves. This can add more depth to his character and explore his self - doubts further.
In a fanfic with this crossover, the interaction of the magic systems would be a central and fascinating aspect. Alchemy in FMA has its own set of rules and limitations, as does magic in Harry Potter. When it comes to the Boggart, the Harry Potter characters rely on their spells and the power of their minds to change the Boggart's form into something humorous. Edward, with his EDS status, could bring in the concept of equivalent exchange. Maybe he could offer something in exchange for the Boggart to leave or change its form in a more permanent way. And the magical energy in the Harry Potter world could interact with Edward's alchemy. It could either disrupt it if they are too different, or it could merge in some ways, allowing for new and creative ways to deal with threats like the Boggart.
In a story where Harry is raised by a boggart, he could have a very distorted view of the world. The boggart, not being a normal caregiver, might not be able to provide the love and stability that a normal family would. So, Harry might be more withdrawn and distrustful. He might also have a hard time making friends at Hogwarts as his upbringing by a boggart could have made him seem strange to other students.
In 'Harry Potter Boggart' fanfics, character development often starts with the revelation of the boggart form. If a character's boggart is public humiliation, it shows their insecurities. As the story progresses, they may face the boggart multiple times and gradually overcome that fear, which is a sign of growth.
Perhaps in the fanfiction, there is a magical tournament where both Harry and Sasuke are participants. One of the challenges involves facing a Boggart. Harry's fear of losing his wand (which is like his life in the wizarding world) and Sasuke's fear of losing his eyesight (since his Sharingan is so crucial) are what the Boggart targets. They initially struggle as they are used to fighting their battles alone. But as the Boggart gets stronger, they realize they need to work together. Harry uses spells to distract the Boggart while Sasuke uses his ninja speed to get behind it and deliver a final blow.