One interesting plot idea could be a story where the Elder Wand has a hidden connection to the Goblet of Fire. Maybe the wand was used in the creation of the Goblet, and this connection is only discovered when a dark wizard tries to manipulate the Goblet's magic using the Elder Wand. The protagonist then has to figure out how to break this connection to stop the dark wizard's evil plan.
Perhaps in a fanfiction, the Goblet of Fire could be a key to unlocking the true power of the Elder Wand. A young witch or wizard discovers an ancient prophecy that links the two magical artifacts. They embark on a journey to find out more about this connection. Along the way, they face many challenges and make new friends and enemies, all while trying to understand how the Goblet and the Wand are related and what it means for the wizarding world.
A plot could revolve around a character who is not in the original series getting hold of the Elder Wand and using it to cheat in the Triwizard Tournament which involves the Goblet of Fire. This causes chaos as the rules of the tournament are being broken and the other champions have to figure out a way to stop this impostor without getting killed by the powerful Elder Wand.
Another plot could revolve around a character who discovers a long - forgotten spell that can only be cast with the Elder Wand, leading to a series of adventures to master the spell and its implications. For example, this spell could have the power to restore lost magic in the wizarding world.
One idea could be exploring the origin of the Elder Wand in more detail. Maybe a story about the first wizard who crafted it and the magic used. Another could be a fanfic where Harry decides not to keep the Elder Wand but instead tries to find a way to destroy it permanently, facing many challenges along the way. And perhaps a plot where the Elder Wand has a mind of its own and tries to manipulate Harry into using it for dark purposes.
One idea could be that Harry has a group of friends from different houses who are all secretly in love with him. They start to form a sort of harem around him during the Triwizard Tournament. For example, Hermione could be using her intelligence to help him in the tournament in a more personal way, and Cho Chang might be more openly affectionate, and then there could be a girl from Beauxbatons who is also drawn to Harry's bravery.
A cool plot could involve a crossover with 'Star Wars'. Picture Harry using the Force in addition to his magic while competing in the Triwizard Tournament. Or perhaps a crossover with 'Alice in Wonderland' where the Goblet of Fire sends Harry down the rabbit hole and he has to navigate Wonderland's strange rules during the tournament.
One idea could be that the OC is a foreign exchange student who has unique magical abilities unknown to Hogwarts. They could help Harry in the Triwizard Tournament tasks in unexpected ways, like using ancient spells from their home country.
Imagine Harry travels back to the time of the Triwizard Tournament. With the Elder Wand, he could expose Barty Crouch Jr. much earlier. This would prevent Cedric's death and change the outcome of the tournament. It would also lead to a different dynamic in the wizarding world as Voldemort's plan to return would be thwarted much sooner.
One idea could be exploring what would happen if a different student was chosen by the Goblet of Fire. Maybe a Muggle - born student who has to face extra prejudice during the Triwizard Tournament. It would add a new layer of conflict and show how the wizarding world reacts to a 'less likely' champion.
One interesting plot idea could be exploring what would happen if a different student was chosen for the Triwizard Tournament. Maybe a shy and overlooked student gets picked, and they have to overcome not only the tournament tasks but also their own insecurities. Another idea could be a love triangle involving characters that were not part of one in the original story. For example, a friendship between a Hufflepuff and a Slytherin turns into a complex relationship when feelings for Harry Potter get involved.
The Elder Wand could be used to control the flames of the Goblet of Fire. For example, a character might use the wand to make the Goblet's flames do specific things like form shapes or spell out messages. This could be used as a form of communication during the Triwizard Tournament or as a way to unlock a hidden mystery within the Goblet.
One idea could be introducing a new character from another universe who accidentally gets transported into the Goblet of Fire timeline. This character could have unique magical abilities that both fascinate and worry the Hogwarts students. For example, they might be able to control time in a different way than Hermione's time - turner. Another plot idea could be that Voldemort discovers a new dark magic spell from this other universe through a mysterious object. This could make him even more powerful and the trio has to find a way to stop him using knowledge from both universes. Also, what if the Goblet of Fire chooses a student from a completely different magical school in this crossover? It would create a whole new dynamic of competition and friendship.