It could be some dark wizards who are not part of the Death Eaters but are still up to no good. They might see Daphne as an easy target during the busy and chaotic World Cup. They could be after her family's wealth or some magical artifact she might be carrying.
Well, perhaps there is some sort of magical accident at the World Cup. A spell goes wrong and endangers Daphne. Harry, being the hero he is, senses the danger and manages to counter the spell just in time. He might use his knowledge of defensive magic, which he has learned from his years at Hogwarts, to keep Daphne safe from the harmful effects of the misfired spell.
Dark wizards or witches who are on a power - hungry spree could be the antagonists. They might see Daphne as an easy target or a way to get to Harry Potter himself. So they kidnap her to lure Harry into a trap.
The Death Eaters are a likely choice. They might target Susan Bones because of her family's connection to the wizarding world. For example, her aunt Amelia Bones was a well - known figure, and the Death Eaters could be after something related to her or the Bones family in general.
In a 'naruto saves korra fanfiction', the villains could be a combination of different forces. There might be rogue benders who have turned to the dark side, using their bending abilities for evil purposes. These benders could be working with some mysterious outsiders who bring in new and unknown threats. Maybe there are ancient evils that have been awakened and they see Korra as a major obstacle. Naruto would then have to face these complex and dangerous foes to save Korra.
Lex Luthor could be a likely villain. He's always devising plans to take down the Justice League, and this time he might have come up with a scheme that almost succeeds, until Batman steps in. For instance, he could create a super - weapon that targets the unique powers of each Justice League member.
Hermione could be involved. She might suspect Daphne of having ulterior motives regarding Harry and try to warn him, which could play into the betrayal storyline in some way, either as a catalyst or as someone who helps Harry deal with the betrayal later.
Daphne could be a fictional character created specifically for this fanfic. She might be a witch from a well - known wizarding family. Maybe she's a classmate of Harry's at Hogwarts or someone who has just heard about his situation and feels compelled to help.
One likely antagonist could be Draco Malfoy. He's from Daphne's social circle and might not approve of her being with Harry. He could try to expose their relationship out of jealousy or because of his pure - blood supremacist views.
The obvious antagonists would be the Death Eaters. They are Voldemort's followers and are often causing trouble in the wizarding world. In this fanfiction, they might be the ones who have put Cedric in danger, either to lure Harry or for some other dark purpose.
The main characters are obviously Harry and Daphne. Harry, the well - known hero from the Harry Potter series, is the one who does the saving. Daphne is the one in need of rescue from the Dementors.