What are some interesting plot ideas in Harry Potter fanfictions involving Septima Vector?

Sure. There are fanfictions that center around the academic side of Hogwarts where Septima Vector plays a role. These can be about students struggling or excelling in her Arithmancy classes. They might also include interactions between different houses' students during her lessons, creating interesting plotlines that don't involve any adult or inappropriate content.

One possible fanfiction could be about Matthew Potter being a long - lost relative of Harry Potter who discovers he has magic later in life. He then has to navigate the wizarding world, facing challenges similar to what Harry did, but also with his own unique story arc.

A fanfiction might focus on a post - Hogwarts scenario where Harry and Ron start a magical business together. They face challenges like dealing with Ministry regulations and competition from other wizarding entrepreneurs. Their friendship is put to the test as they try to make their business a success while also maintaining their family lives. Harry might be worried about how his fame could either help or harm the business, and Ron has to deal with his insecurities about always being in Harry's shadow, even in this new venture.

In some 'Harry Potter' fanfictions, a dog could be used as a means of transportation. Instead of the traditional broomsticks or thestrals, a magical dog could be trained to carry riders. This would change the dynamics of travel within the wizarding world. Also, there could be a story where a dog is the key to unlocking a hidden magical realm within Hogwarts. The dog might lead the characters to a secret passage or room that has been long forgotten, and inside could be a world full of new spells and magical creatures.

One interesting 'Harry Potter' fanfiction involving venom could be about a magical creature that has a venomous attack and how Harry and his friends deal with it. For example, a new breed of snake that has a venom which can cause magical paralysis. They might have to find an antidote in the Forbidden Forest.

One idea could be a crossover where Harry and Neville end up in the Naruto universe. They could learn chakra techniques and use their magic in new ways. For example, Harry might combine his Patronus charm with a chakra-based attack. Neville could use his knowledge of Herbology to discover new medicinal plants in the Naruto world.

There might be a fanfiction where Harry Potter teams up with a member of the Black family, like Sirius Black if he were still alive in the story. They could go on an adventure to uncover a mystery that is related to both the Potter and Black family legacies. For example, they might find a hidden artifact that was once owned by an ancestor common to both families and has the power to change the fate of the wizarding world.

A plot could be about a student who has a phobia of large groups (agoraphobia). At Hogwarts, there are always big gatherings in the Great Hall, Quidditch matches, etc. This character could struggle to attend these events. Their friends could try to help them gradually face their fear, and in the process, they might discover a magical solution or just the power of friendship to overcome it.

One idea could be a story where a young Death Eater in training is forced to use the Cruciatus Curse on an innocent by his family, but he has a change of heart. He then has to deal with the consequences of defying his family's wishes and trying to protect the victim from further harm.

One plot idea could be that Urahara Kisuke somehow ends up in the Harry Potter universe. He might use his unique inventions and skills from the Bleach world to help Harry and his friends in their fight against Voldemort. For example, his kido skills could be translated into new spells in the wizarding world.