Who could be the main antagonists in a 'Black Butler High School AU Fanfiction'?

One idea could be that Ciel is the new student council president, trying to reform the school's old - fashioned rules while dealing with a rival group led by Alois. Sebastian could be his loyal butler and also a star student in various subjects, secretly helping Ciel with his plans.

There could also be Mordred as a younger student who looks up to Merlin. He might be a bit of an outcast too because he has some strange abilities. Gwaine could be the class clown who befriends Merlin and is always getting into trouble. Percival could be the gentle giant, an athlete on Arthur's team who also befriends Merlin and protects him from bullies at school.

Danzo could be a great antagonist in this 'naruto highschool au fanfiction'. He could be the strict school principal who enforces very strict rules and has a hidden agenda. He might not like Naruto's free - spirited nature and try to expel him. Also, Kabuto could be a student who is under Danzo's influence and causes trouble for Naruto and his friends.

In this kind of fanfiction, Gaara could start as an antagonist. He's the new kid from another school who transfers in. He has a very cold and intimidating demeanor. He gets into fights with Naruto and his friends because he has his own ideas about how things should be in the school. He doesn't trust easily and thinks everyone is out to get him. But as the story progresses, he could turn into an ally. Also, Danzo could be an antagonist. He's a strict, old - fashioned teacher who doesn't like Naruto's unruly behavior and tries to expel him from school at every chance he gets.

Obviously, Harry could still be a main character. He'd be the brave new kid in high school, trying to make friends and figure out his place. Hermione would also be there, the super - smart girl who is always acing her classes and getting involved in every club. Ron could be Harry's best friend, the laid - back but loyal guy. And Draco could be the rich, snobby kid from the 'popular' group who constantly gives Harry a hard time.

One possible antagonist could be a popular girl in school who is jealous of Sakura's popularity and tries to undermine her at every turn. For example, she might spread false rumors about Sakura or try to steal her friends. Another could be a strict teacher who doesn't believe in Sakura's abilities and is always giving her a hard time, like constantly doubting her work in class or not allowing her to participate in certain school activities.

A jealous classmate could also be an antagonist. Maybe someone who has a crush on Adam and doesn't like that he's starting to show an interest in Belle. This person could try to sabotage Belle's reputation at school by making up lies about her or trying to get her in trouble with the teachers, all in an attempt to drive a wedge between Belle and Adam.

A group of rogue reapers. They don't follow the rules of the Death Gods and are causing chaos in the afterlife and the living world. Their actions start to affect Ciel's plans and he has to deal with them, which is difficult as they have unique powers related to death and time.

If we swap Star and Marco, then the main antagonists could be those who were previously minor annoyances for the other character. For example, if Marco is now in Star's role, Ludo, who was a main antagonist for Star, could be an even bigger threat as Marco might not have Star's natural magical intuition to deal with him.

Perhaps there's a new villain, a powerful sorcerer who has a vendetta against Percy. The sorcerer discovers that Percy is now at high school and decides to target the school. He uses his magic to create illusions and manipulate the minds of the students and faculty, turning them against Percy. The sorcerer might also be after the secrets Percy learned in Tartarus, thinking it can give him more power.