What are some possible storylines for a mute child in Harry Potter fanfiction?

Another storyline might involve a magical artifact that accidentally causes Harry to regress mentally. He could then start seeing Hogwarts in a completely different light, like it's a huge, exciting playground. He might be more interested in exploring the castle's secrets for the fun of it rather than for any serious purpose, and his relationships with his professors also change as they have to deal with this new, child - like Harry.

One possible storyline could be Harry's struggle to prove his innocence while in Azkaban. Maybe he discovers some dark secrets within the prison walls that are related to a larger threat to the wizarding world. Another could be his attempts to escape and the friends he makes or enemies he encounters during the process.

One possible storyline could be that the child is a result of a relationship Harry had during his later years at Hogwarts that was kept secret. Maybe it was with a foreign witch he met during one of his adventures outside of Hogwarts. The child could inherit Harry's magical abilities and also some of his personality traits like his courage and sense of justice. Then the story could focus on how the child discovers his or her true identity and the legacy of being Harry Potter's offspring.

One possible storyline could be that a powerful magic spell is cast on Harry by a dark wizard who wants to disrupt the wizarding world. This spell forces him to experience a transformation in his gender identity. Harry then has to struggle with not only his new identity but also how the people around him, like his friends Ron and Hermione, react to this sudden change.

A story could be that Voldemort has somehow tapped into the power of the Greek underworld. Harry, as a Greek demigod, has to use his unique powers and the knowledge of Greek mythology to stop Voldemort. Along the way, he teams up with other demigods and wizards. He also has to face the trials set by the Greek gods themselves, as they are not entirely sure if they should support a wizard in their demigod affairs.

One possible storyline could be that the wizards from the Harry Potter world discover the Power Rangers' technology. They might be intrigued by the Rangers' morphers and Zords, thinking they could use them for their own battles against dark magic. For example, Hermione could study the technology to see if it could be adapted to protect Hogwarts better.

The OC could be part of a prophecy that involves their Sharingan. In the fanfiction, they are the only one who can see the true form of a new, powerful dark magic that is starting to spread through the wizarding world. With their Sharingan, they can trace the source of this magic back to an old, forgotten wizard who was banished long ago. Along the way, they face many challenges, including distrust from the Ministry of Magic and jealousy from other students. But in the end, they are able to save the wizarding world with their unique ability.

A possible storyline could be that Hogwarts is invited to participate in an international Academic Decathlon that includes both wizarding and Muggle schools. The Hogwarts students have to quickly learn about Muggle academic subjects while also showing off their magical knowledge. There could be challenges like a magical obstacle course that also tests scientific knowledge, and a debate where they have to use both magical and Muggle facts.

One possible storyline could be that in a final battle against Voldemort, Harry sacrifices himself in a way that no one could reverse. For example, he might use a powerful spell that requires his life force to destroy the last of Voldemort's Horcruxes. Another could be that he succumbs to a dark curse that was placed on him long ago, which was dormant until a certain event triggered it. Maybe a character that was thought to be an ally actually turned out to be a double - agent and cast a fatal spell on Harry.

One possible storyline could be that after the war, Harry and Fleur start to bond over their shared experiences of trauma and loss. They find comfort in each other and gradually fall in love. Another could be a story where Fleur has always had a secret admiration for Harry, and when she realizes he has feelings for her too, they decide to get married. Maybe in this fanfiction, they also have to face the challenges of different cultures, as Fleur is from Beauxbatons and Harry is from Hogwarts.