Cinderella's fairy godmother could also turn out to be the antagonist. She might have given Cinderella false hopes and used her to fulfill some self - serving prophecy. Maybe she has her own dark secrets and is manipulating Cinderella all along.
Cinderella's step - mother could be more than just a mean step - parent in a dark fanfiction. She could be an evil witch who has been draining Cinderella's life force or trying to steal her soul. And her stepsisters could be her accomplices in this dark plot.
The stepmother is an obvious choice. In a time - twist scenario, she could use her knowledge of the past to try and prevent Cinderella from ever going to the ball in the first place. Maybe she finds a way to change the events that led to the fairy godmother helping Cinderella.
Perhaps a group of dark side cultists could be the main antagonists. They idolize the power of the dark side and see Ahsoka as a prime candidate to join their ranks. When she refuses at first, they start to hunt her down, but in the process, they unknowingly push her closer to the dark side, creating a complex dynamic where they are both the pursuers and the inadvertent cause of her fall to the dark side.
The Green Goblin could be a great main antagonist in a dark fanfiction. He could be even more deranged and have a more elaborate plan to destroy Spider - Man, not just physically but also mentally by targeting his relationships.
The World Government could become the main antagonist. They would see Luffy's new power as a threat, especially if he starts using it in ways that oppose their rule. They might send out their strongest agents, like the Admirals, to take Luffy down. The Admirals could have developed new techniques to deal with the dark dark fruit powers, making them a formidable foe for Luffy.
It could be an unknown ninja who has been secretly studying dark energon for years. He wants to use it to take over the ninja world, believing that the power of dark energon will make him invincible.
Well, obviously Dark Gaia itself could be the main antagonist. It has the power to cause chaos and destruction, and Sonic would have to stop it from wreaking havoc on the world.
It could be a powerful sorcerer. In the Dark Skies world, a sorcerer with dark magic could oppose Jesse. This sorcerer might be after the same magical artifacts as Jesse or simply wants to rule the Dark Skies with an iron fist.
It could be a rogue Dark Jedi who has escaped from his own Order and sees the Naruto world as a new place to spread chaos. He might be seeking powerful chakra sources to fuel his Dark Side powers.
It could be Sasuke. If Sasuke continues to pursue his own vendetta in a more extreme way and Naruto's attempts to bring him back fail, Sasuke could become the main antagonist. Their rivalry could turn into a full - blown battle for power and ideology, with Naruto being pushed to his limits and potentially turning dark in the process of trying to stop Sasuke.
It could be an ancient dark wizard who has been manipulating events from the shadows. This wizard might see Elsword as a powerful tool and has been slowly influencing him to turn dark. The wizard could be using dark magic to cloud Elsword's mind and make him more susceptible to negative emotions.