Another plotline could involve Harry's relationships at school due to his academic success. He could become a sort of academic rival to Hermione in a friendly way. They compete to get the best grades in every subject, which in turn strengthens their friendship as they learn from each other. Also, teachers start to trust him more with important tasks around the school because of his good performance.
A third plotline could be that Harry's school success leads to him being chosen for a special academic program or exchange. He travels to another wizarding school, where he has to prove himself all over again. His skills from Hogwarts help him adapt quickly, and he ends up making new friends and learning new types of magic. This experience broadens his perspective on the wizarding world and makes him an even better wizard when he returns to Hogwarts.
A possible plotline could be Harry being sent to a different school as part of an exchange program. At the new school, he has to prove himself all over again. He meets new friends and enemies. For instance, if it's Beauxbatons, he might be challenged by the students who think he's just a famous name from Hogwarts and not really that talented.
One possible plotline could be Harry struggling to keep up with his magical training due to his anemia. He might have to find alternative ways to gain strength for spells.
One possible plotline could be Harry struggling to accept hugs or physical contact from his friends, causing misunderstandings among them.
One possible plotline could be that Harry somehow gets transported to the world where Izaya exists and they form an unlikely alliance. Maybe they team up to solve a mystery that is plaguing both their worlds.
A possible plotline could involve Harry being transported to the world of Alduin and being mistaken for Alduin at first. As he tries to figure out what's going on, he has to learn about Alduin's powers and how to control them. Meanwhile, the real Alduin might be on the loose and Harry has to either stop him or find a way to co - exist with him. There could also be a plot where Harry uses his knowledge from the wizarding world to bring about new changes in the world of Alduin, which might be met with resistance or acceptance from the natives of that world.
One possible plotline could be that a character from Harry Potter accidentally ends up in the world of High School DxD. For example, Ron could be transported there and have to figure out how to get back while dealing with the devils and angels in that world.
Well, a plotline might involve Harry being hunted by those who oppose the mixing of wizard and vampire lineages. Or perhaps he is the key to a prophecy that involves both the wizarding and vampire worlds. It could also be that he has to hide his newfound heritage from his friends at Hogwarts for fear of being ostracized. There could be a lot of internal conflict as Harry tries to understand his place in this new family tree and what it means for his identity.
One possible plotline could be Harry being easily tricked by dark wizards who take advantage of his naivete. For example, they might convince him to perform dangerous spells or go to forbidden places. Another could be that he misinterprets the intentions of his friends, causing some rifts in their relationships until he eventually learns the truth. Maybe he also gets involved with some new magical creatures that he wrongly believes are harmless because of his naivete.
Perhaps in some 'harry marries snape fanfiction', there could be a magical accident that binds their fates together. At first, they resist the connection, but as they get to know each other better, they find common ground and fall in love, leading to marriage. This could involve a lot of emotional turmoil and self - discovery for both characters.
One possible plotline could be about the Weasley family trying to improve their financial situation. Maybe they come up with a new business idea in the wizarding world, like a magical product that becomes a huge success and changes their economic status. Another could be a story about how the Ministry of Magic regulates the financial system in the wizarding world, and there are some characters who try to manipulate or reform it.