Maybe in this fanfiction, Harry discovers he has a long - lost werewolf relative. Through some dark magic plot, their blood connection causes him to start turning into a werewolf. As a werewolf, he finds himself drawn to the werewolf packs in the Forbidden Forest. He has to decide whether to embrace this new part of himself or fight against it, all while still dealing with Voldemort's threats and the ongoing battle in the wizarding world.
One possible plot could be that Harry is bitten by a werewolf during one of his adventures outside of Hogwarts. He then has to struggle with his new identity as a werewolf. He might face discrimination from some in the wizarding world who fear werewolves. He could also try to find a way to control his transformations, perhaps with the help of his friends like Hermione who would research potions or spells to ease his condition.
Well, it could be that there's a spell gone wrong that turns Harry into a werewolf. As a result, he is shunned by some in the wizarding world, but he also finds a community of outcasts, including other werewolves. Together, they work towards changing the perception of werewolves in the wizarding society and Harry also has to figure out how to control his new form.
The Ministry of Magic could be a main antagonist. They have a history of being discriminatory towards werewolves. They might see Harry as a threat now that he's a werewolf and try to lock him up or restrict his movements. For example, they could pass new laws specifically targeting him, like making it illegal for him to attend Hogwarts as a werewolf.
Well, one possible plot could be that Harry, as a werewolf, somehow gets transported to the RWBY world. He has to hide his werewolf identity at first, but as he gets involved in the battles against the Grimm, his werewolf powers start to become an advantage. He might form an alliance with some of the RWBY characters who initially fear him but later come to understand and accept him.
Maybe Harry Potter uses his powerful magic skills to take over the wizarding world. He could start by defeating all his enemies like Voldemort in a very quick and decisive way and then establish his own rules.
In the fanfiction, Harry might be cursed to transform into a dragon periodically. He then has to figure out how to control this new form. He could meet other magical creatures that are either scared of him or intrigued by his dragon form. He might also find that his dragon form gives him unique powers that he didn't have as a human wizard, like the ability to fly faster or breathe a more powerful type of fire.
Well, perhaps Harry Potter is magically transformed into a Naga. He could then struggle with his new form, having to adapt to the snake - like body. Maybe he discovers new magical abilities related to Nagas, like a special connection with the underworld or some kind of venom - based magic.
Well, perhaps Harry could inherit some of the Hanyou traits like enhanced senses. He might use his newfound abilities to detect dark magic more easily. For example, his sense of smell could help him identify the presence of dark wizards even before they cast a spell.
One possible plot could be that Harry, as a banshee, uses his newfound abilities to warn the wizarding world of impending dark magic threats. His banshee screams might be able to disrupt dark spells or alert people to the presence of Death Eaters. For example, he could sense Voldemort's movements in a more acute way and use his screams to drive away the dark forces when they are about to attack Hogwarts.
One possible plot could be that Harry Potter discovers some hidden good in Draco Malfoy. Maybe he sees Malfoy struggling with the expectations of his family and the dark side he's being pushed towards. This new understanding makes Harry start to admire Malfoy's inner strength to resist, in a way, and he becomes a sort of 'fan' in the sense that he respects Malfoy more.
He could start by using magic in the kitchen. For example, he might use a spell to make the ingredients fly to the pan at just the right time. He could create unique dishes inspired by his Hogwarts experiences, like a potion - flavored soup. Maybe he'd open a wizard - themed restaurant where muggles and wizards alike could enjoy his magical cooking.