Who could be the main antagonist in 'bella is secretly a volturi fanfic'?

The Volturi Queen herself could be the main antagonist. If she views Bella as a threat to her power or the Volturi's way of life, she would be a very powerful foe. She could use her influence over the Volturi guards and her own powers to try and stop Bella.

Perhaps there is a rogue vampire within the Volturi's ranks who doesn't want Bella and Alice there and tries to undermine their purpose. This vampire could be jealous of their relationship or afraid that they will expose some of the Volturi's secrets.

It could be a character who somehow discovers Izuku's secret and tries to use it against her. Maybe a rival at school who is jealous of Izuku's progress and sees this as a way to get her expelled or discredited in the hero community.

Perhaps a rival adventurer who discovers Bilbo's secret and tries to use it against her. This antagonist could be jealous of Bilbo's place in the group and sees her secret as a way to undermine her and take her position. He might spread rumors or try to create situations where Bilbo's secret is likely to be revealed.

One possible plotline could be that Bella tries to hide her admiration for the Volturi from the Cullens. She might secretly collect information about them or have dreams about their world.

It could be one of the traditional Volturi members who oppose Edward's presence. They might see him as an outsider who could disrupt their long - established order. For example, Caius might be against Edward joining as he's often portrayed as more rigid and less accepting of new vampires in the Volturi.

There could be other vampires that Bella meets during her time as a vampire before the Volturi. For example, some lone vampires who are also trying to stay out of Volturi's radar. They could become her allies or foes depending on their motives.

It could be a new vampire who is jealous of Bella's relationship with the Cullens. This vampire might have some special power that allows them to manipulate memories, like Alice's memories of Bella. They see Bella as a threat to their own plans in the vampire world, so they try to create chaos by making Alice forget about her.

A jealous student could be the main antagonist. This student might have a crush on Alice and see Bella as a threat to their relationship. They could start spreading rumors about Bella, trying to make her look bad in front of Alice and the other students.

Perhaps a jealous rival. This person might be a male who is threatened by Ed's success or popularity. When they discover Ed is a girl, they could use this secret to try and drive her out of the group or community she's in. They might spread rumors or create problems for her.