Who could be a good antagonist in 'an unorthodox hero fanfic'?

It could be a modern - day villain who wants to use the power of the ancient heroes for his own evil purposes. He might be jealous of Percy's connection to the ancient heroes and try to stop him at every turn.

It could be a new villain who has the power to manipulate time. This villain would be constantly changing the past and future to create chaos in Paris. Chat Noir would have to figure out how to stop this power. Maybe the villain is doing it to find a powerful artifact from the past that was hidden to prevent it from being misused.

The antagonist could be a super - villain who has a personal vendetta against the hero. He might have used his influence to make the hero's life a living hell and made everyone think the hero was worthless, like garbage. The hero's revenge is all about taking down this super - villain and restoring his own honor and the safety of the world that the villain has been threatening.

Cheetah could be a great main antagonist. Her super - speed and predatory nature would make her a formidable foe for The Flash and the DC Super Hero Girls. She could be stealing some important artifacts that are related to speed and power, forcing The Flash to team up with the girls to stop her.

Roman Torchwick would be an obvious choice. He already has a criminal background in the RWBY series. He could return with a new and more devious plan, perhaps teaming up with other villains to cause chaos.

Most likely, the 'terror' itself is the antagonist. It's what the hero has to fight against.

A rogue ninja from the Whirlpool Village who resents the Kage and wants to take over the village's power. He could see Naruto as an obstacle in his path to domination, especially if Naruto is trying to help the current Kage or revive the village.

One idea could be to give the hero a unique power that is not typically seen in the original story, like the ability to communicate with animals. This would add a new dynamic to the character and open up different storylines, such as using the animals to gather information or help in battles.

Dormammu could also be a formidable antagonist. His dark magic and his desire to expand his dark dimension could put him in conflict with Ghost Rider. If there's a crossover with the Fantastic Four world, he could use his powers to try and take over Earth while Ghost Rider tries to stop him, and the Fantastic Four might get caught in the middle.

In a Wiress Hunger Games fanfic, a Capitol official who has a personal vendetta against Wiress could be an antagonist. Maybe Wiress uncovered some of their secrets during her time in the Capitol, and now they are out to get her, using the Hunger Games as the perfect opportunity to get rid of her.