One idea could be that Harry has to hide his new werewolf form from his friends at Hogwarts. He might struggle with the stigma associated with werewolves in the wizarding world, even though his friends know him well. Another could be that he discovers new magical abilities related to his werewolf form that help him in his fight against Voldemort. For example, enhanced senses that allow him to detect dark magic more easily.
In this fanfiction scenario, Harry becoming a werewolf could cause a rift in the wizarding community. Some might see him as a threat, while others, like the Weasley family, would stand by him. The story could focus on how he copes with this new identity. He could start to understand the werewolves' perspective more, and try to bridge the gap between the wizarding world and the werewolf community. He might also have to deal with the Ministry of Magic's attempts to control or eliminate him because of his new form.
One idea could be that as a girl, Harry has to deal with different social expectations in the wizarding world. For example, she might face more restrictions on certain adventures compared to when she was male. Also, her relationships with Ron and Hermione could change in interesting ways. Ron might be more protective, while Hermione could become a closer confidant as they share more 'girl - specific' experiences.
One idea could be a werewolf character finding their true mate among the Harry Potter characters. Maybe a werewolf who has always felt like an outcast in the wizarding world finally meets someone who accepts them completely. This could lead to a story of self - discovery and acceptance for both the werewolf and their mate.
Well, perhaps in the fanfiction, Harry becoming a werewolf leads to a rift between him and some of his friends who are afraid of him now. But then he meets other werewolves who teach him how to control his transformation and he uses this newfound control to his advantage in the fight against the dark forces. He could also form an alliance with the werewolves in the wizarding world, which changes the power dynamics.
One idea could be that as a dragon, Harry uses his new form to protect Hogwarts in a way he couldn't as a human. He could fly around the castle, breathing fire at any dark forces approaching. Another could be that his dragon form has unique magical abilities that are connected to his status as 'God Harry Potter', like being able to see into the future to prevent disasters.
Another interesting concept is Harry turning into a cat. He could then slink around Hogwarts unnoticed. He could spy on Snape or Malfoy, gathering information. His cat form would give him the ability to be stealthy and get into small spaces, like the hidden passages in the castle.
Perhaps a fanfic where Lily Potter's spirit is able to communicate with Harry Potter during his difficult times at Hogwarts. She gives him advice and guidance that helps him through his struggles, like dealing with Snape's complex feelings towards him, or facing the challenges of the Triwizard Tournament. This would add an emotional and magical element to Harry's journey.
One idea could be exploring how Harry copes with his new werewolf form at Hogwarts. Maybe he has to hide it from his friends at first and deal with the fear of being discovered. Another could be his interactions with other magical creatures who are more accepting of his werewolf side.
Here's a plot. Harry turns into a dragon in the Forbidden Forest. At first, he's scared and confused. But then he realizes he can fly and explore parts of the forest that are unreachable as a human. He discovers a hidden magical artifact while in his dragon form. However, the Ministry of Magic hears about his transformation and wants to capture him, thinking he's a dangerous uncontrolled magical being. So, Harry has to evade capture while also trying to figure out how to turn back to his human form and clear his name.
One plot idea could be that Crookshanks discovers a hidden passage in Hogwarts that leads to an ancient wizarding library. He then leads Hermione to it, and they find a powerful spellbook that helps them in their fight against the dark forces. Another could be that Crookshanks has a secret ability to communicate with other magical creatures in the Forbidden Forest and he enlists their help to save Harry from a dangerous situation. Maybe he can talk to the centaurs and they come to the rescue when Harry is surrounded by Death Eaters.