What are some interesting plot ideas for Harry Potter 4th year fanfiction?

Another interesting plot could be that Harry's connection to Voldemort causes some strange magical disruptions during the Triwizard Tournament. These disruptions seem like accidents at first, but Harry gradually realizes they are being caused by his own dark - side related powers that are being awakened in his fourth year.

One idea could be that Harry discovers a new, hidden magical ability within himself that helps him in the final battle against Voldemort. For example, the ability to communicate with the spirits of Hogwarts founders for guidance. Another could be that the relationships between the characters take a different turn. Maybe Hermione and Ron have a huge fight early on and Hermione teams up with Draco for a while out of necessity, which changes the dynamics of the whole group. Also, Neville could have an even more prominent role, leading a secret group of students who are training in a new form of magic that they hope will give them an edge in the fight.

A plot could be that Harry has premonitions about the Triwizard Tournament tasks before they happen. These premonitions are not clear at first, but as he gets closer to each task, he starts to understand them better. It adds an element of mystery and foreshadowing to the story.

One idea could be exploring more of the backstories of the other schools' students who came for the Triwizard Tournament. For example, delving deeper into the life of a Durmstrang student and how their magic education differs from Hogwarts.

Perhaps in the fanfiction, we could see a different side of the foreign students. Like, the Beauxbatons and Durmstrang students could have their own hidden agendas. One of them might be in love with Harry and tries to protect him during the tournament tasks. This would create a whole new dynamic of relationships and loyalties within the story.

A really cool plot twist might be that Hermione finds a way to travel back in time to change certain events that led to Voldemort's rise. She has to be extremely careful not to disrupt the whole timeline while trying to save the wizarding world. It's a complex and exciting idea that can lead to a lot of interesting scenarios in the 7th year of the story.

One interesting plot twist could be that in the AU, Neville Longbottom is the one secretly chosen for the Triwizard Tournament instead of Harry. It would completely change the dynamic as Neville has his own insecurities and strengths that would play out differently in the challenges.

A really cool plot idea would be if there was a new magical creature introduced in Harry's third year that was related to the Dementors in some way. Harry could have to learn about this creature to better understand how to combat the Dementors and it could add a whole new layer to the story.

Another plot could revolve around Harry's Occlumency lessons. In fanfiction, it could be that instead of just trying to block his mind from Voldemort, he actually manages to use Occlumency to his advantage. He could start to plant false thoughts in Voldemort's mind through their connection, leading Voldemort astray in his plans.

One interesting plotline could be Harry's struggle with his new role as a leader in Dumbledore's Army. He has to deal with the pressure of teaching his peers and also keeping the group a secret from Umbridge.