Who could be the main antagonist in 'harry becomes a vampire fanfiction'?

Perhaps a powerful vampire lord who sees Sookie as a threat to his power. Since she was once human and has connections to both worlds, he might fear that she could rally other vampires and humans against him. He could try to eliminate her by any means necessary, leading to a lot of action - packed scenes in the fanfiction.

It could be an old and powerful vampire who sees Hermione as a threat to his rule. Since Hermione is a very intelligent witch - now vampire - she might be able to figure out a way to undermine his power.

It could be an old and powerful vampire lord who sees Natsu as a threat to his rule. Since Natsu is a new and different kind of vampire, the lord might want to eliminate him.

Another possibility is a vampire who wants to use Ethan for his own gain. He might try to manipulate Ethan into doing things that are against his will. This vampire could be part of a powerful vampire clan and wants Ethan to be his puppet so that he can gain more power within the clan.

Another option is a powerful vampire coven leader who wants to use Jacob for his own purposes. When Jacob refuses, the coven leader turns against him and becomes the main source of conflict in the fanfiction.

The Ministry of Magic could be the main antagonist. They might view Harry's fascination with Dementors as a sign of him turning to the dark side. So they try to stop him from his research and exploration of Dementors, fearing he'll use their powers for evil. After all, Dementors are associated with dark magic in the eyes of the Ministry.

There could also be new antagonists. For example, some of the more traditional wizarding families who are against the idea of a female Harry. They might see her as a threat to the old - fashioned ways of the wizarding world and try to undermine her.

Draco Malfoy could be a main antagonist. Since Harry becoming a prefect is a sign of prestige and power, Malfoy, who is always jealous of Harry, would try to undermine him. He might spread false rumors about Harry misusing his prefect powers or try to get him in trouble with the professors.

Maybe a dark wizard who wants to capture the phoenix - Harry for his own evil purposes. This wizard could be after the unique powers that a human - turned - phoenix like Harry would possess. He might want to use Harry's phoenix form to gain immortality or to spread dark magic across the wizarding world.

There could be a jealous student. This student might be envious of Harry getting all the attention with his snake - related adventures. So, they would act as an antagonist by trying to undermine Harry's efforts in the snake fanfiction world. They could spread false rumors about snakes being dangerous or Harry's intentions being dark, causing trouble for Harry among his peers and teachers.