Well, one possible plot twist could be that Harry discovers the new school has a hidden magical artifact that is both a great power source and a danger. Another could be that the teachers at the new school are secretly working for an old enemy of Harry's. Or perhaps Harry finds out he has a long - lost relative among the students at the new school.
A really interesting plot twist could be that the new school's sorting system is completely different from Hogwarts. Instead of houses, they have groups based on different magical abilities. Harry, being used to the Hogwarts way, struggles to fit in at first. But then he realizes that this new system is actually a better way to develop his magic. This would not only be a twist for Harry but also for the readers who are used to the traditional Hogwarts setup.
There might be a plot twist where the new school is actually a front for a dark magic experiment. Harry could start noticing strange behavior from the students and staff, like unexplained disappearances or odd magical occurrences. Maybe he uncovers that the school's headmaster has a dark past and is using the students for some evil purpose. It would be a big shock for Harry and would completely change the direction of the fanfiction.
He could make friends with a shy but extremely talented wizard who has been overlooked by others. Maybe a girl who is really good at potion - making but is too introverted to show off her skills. Another new friend could be a joker - type character who always lightens the mood with his funny magic tricks. And there might be a tough - looking guy who is actually a big softie inside and becomes Harry's loyal friend.
In this 'harry potter changes the north fanfiction', it's possible that Harry Potter is sent on a mission to the North to stop some sort of dark magic that is spreading there. He has to adapt to the unique magical and non - magical aspects of the North. He could end up using the local knowledge and magic to his advantage, and in the end, not only defeats the dark magic but also changes the North in terms of its magical and social structure. He might inspire the local wizards or witches to be more open - minded and collaborate with the rest of the wizarding world.
In this fanfiction, a great plot twist could be that the Slytherin character has a hidden identity as a member of an ancient magic - protecting group. The betrothal to Harry is part of a bigger plan to unite the houses against a new, emerging dark force. As they come together, they face a lot of opposition from both sides, Gryffindor and Slytherin, but through their relationship, they start to bridge the gap between the two houses.
One possible plot twist could be that Harry discovers some hidden magical ability within himself that is related to his new family with Dean. Maybe it's a unique type of magic that only his new family line has.
One possible plot twist could be that as a girl, Harry has an even stronger connection to magic related to femininity, like a special bond with female magical creatures. Another could be that she faces different social challenges in the wizarding world, perhaps more pressure to conform to traditional female roles while still being a hero.
In this fanfic, there could be a plot twist where the Hogwarts houses' traditional rivalries are turned on their heads. Instead of Gryffindor vs Slytherin, etc., a new threat makes them all have to work together in ways they never expected. The characters might have to overcome their long - held prejudices and form new relationships to face this common danger, which is a big change from the norm in the Harry Potter universe.
One plot twist could be that Snape is actually mentoring Harry on behalf of Dumbledore from beyond the grave. Maybe Dumbledore had some secret plan that he didn't get to fully execute, and Snape is now following through with it. Another could be that Snape discovers a new magical ability in Harry that no one else knew about.
Well, a really interesting plot twist could be his relationship with the other Hogwarts houses. He might not have the same automatic connection with Gryffindor. Instead, he could be more inclined towards Slytherin values, which would completely change his dynamic with Ron and Hermione. Maybe he would form closer friendships with Slytherin students right from the start. Also, his views on pure - blood supremacy could be more complex as he is raised in a family that might have some traditional views on blood purity.
In some fanfictions, Bellatrix might kidnap Harry with the intention of turning him to the dark side. She could try to corrupt him by showing him the power and 'glory' of the dark magic she practices. This would be a huge psychological battle for Harry as he has always been firmly against the dark arts.
A really interesting plot twist might be that Voldemort is being controlled by an even darker force, and Harry has to figure out a way to break that control while being held captive. Or perhaps Harry's friends, thinking he is dead, accidentally start a chain of events that end up helping Harry escape in a very unexpected way. For example, Hermione might cast a spell that was supposed to be for protection but ends up creating a portal right in Voldemort's lair.