There could also be some foreign dark wizards who have come to the World Cup with the intention of starting trouble and they end up facing Harry in a fight. These wizards might have different styles of magic that Harry has to quickly adapt to.
It could be some Death Eaters who are causing chaos at the World Cup. They might be trying to disrupt the event and target Harry.
Maybe there are some rogue wizards who are jealous of Harry's fame and power. They see the World Cup as an opportunity to take him down.
Voldemort could be one of his main opponents, even in the game world. Voldemort might try to use dark magic within the game to defeat Harry. Another could be Draco Malfoy. Draco would be jealous of Harry's success in the game and try to undermine him at every turn, using his family's influence within the game's magical society.
One exciting scene could be Harry using his Patronus charm to fend off dark wizards. The Patronus, a bright and powerful form, would cut through the darkness.
Voldemort is a common one. In many fanfictions, their duels are epic battles of good vs evil, with Harry using his duelist skills to outwit Voldemort.
His friends from Hogwarts like Hermione and Ron would most likely support him. They have always been by his side through thick and thin in the original story, so in the fanfiction, they would continue to support Harry in his fight against the Ministry.
Hermione could help. She's very smart and could research about the dragon's weaknesses.
In Harry Potter fanfic, Viktor Krum is a character who could be related to the World Cup in various ways. For example, his participation in the Quidditch World Cup could be a central plot point. Fanfic writers might explore his experiences during the event, his interactions with other characters like Harry Potter, and how the World Cup atmosphere affects him.
One challenge could be controlling the assassin's violent tendencies. Since the person is being groomed to be an assassin, it's likely they have a natural inclination towards violence, and Harry has to find a way to temper that while also teaching self - defense.
He might face political intrigue. There are likely those in the Wizengamot who oppose him due to his past actions and his association with Dumbledore. Also, he has to deal with the complex and often archaic laws and traditions of the wizarding world which could be a huge obstacle.
Well, in such a fanfiction, Harry could have found a magical fire - producing object that gives him the ability to fight the dragon with fire. He might have to learn how to handle this new power quickly while in the heat of the battle. The dragon, on the other hand, would use its natural abilities like flying and breathing fire in return. It would be a battle of wits and power.
Well, it would be quite a strange yet exciting scenario. Harry's magic skills would surely give the Allies an edge. He could use spells like 'Expelliarmus' to disarm enemy soldiers or 'Accio' to retrieve important items or intel. His invisibility cloak would also be a great asset for stealth missions.