How to create a villain in Miraculous Ladybug fanfiction?

Let's make a Kwami named Luma. Luma could be a Kwami related to stardust. Its Miraculous could be a star - shaped hairpin. The superhero with this Miraculous would be able to fly faster than normal superheroes, and also have the ability to create a shield made of stardust that can protect from most attacks.

One idea for a 'Miraculous Ladybug' thief OC fanfiction could be that the thief OC is stealing artifacts that are actually magical items related to the Miraculouses. The OC could be doing it for a noble cause, like trying to prevent a greater evil from getting their hands on them. Maybe they have a tragic backstory that led them to this path. For example, their family was wronged by someone who wanted to use the Miraculous for bad, and now they are trying to keep the artifacts safe by stealing them from those who would misuse them.

It could be a new villain created specifically for the fanfiction. Maybe an ancient sorcerer who was trapped for centuries and now wants revenge on the modern - day heroes. He has the power to turn things to stone and sees Ladybug as the main threat to his plans.

A possible main villain could be a character from Ladybug's past who has discovered her identity and is using that knowledge to create chaos. They could be blackmailing her or trying to steal her Miraculous by setting up elaborate mysteries and traps for her to solve.

It could center around the son of a villain who discovers a miraculous of his own. This miraculous might be different from the ones Ladybug and Chat Noir have. He then has to learn how to use it while also dealing with the fact that his family is against the heroes. His journey could be about finding his own identity, whether he wants to follow in his family's footsteps or become a hero in his own right. He may also face challenges from other villains who don't trust him because of his family ties.

A villain that has the power to steal emotions could be a great choice. Imagine this villain targeting Edendaphne's friends and allies, draining their positive emotions. Edendaphne would have to find a way to not only stop the villain but also restore the emotions of those affected. It would be a very emotional and intense story.

Hawkmoth is an obvious choice. His whole mission is to obtain the Miraculouses, and in a death fanfiction, he could succeed in a more devious way than in the original series, directly or indirectly causing Ladybug's death.

An evil alien warlord could be the main villain. This warlord could be bent on conquering Earth and other planets in the universe. He might see the Miraculouses as a threat and try to destroy Ladybug and Chat Noir first.

A new character could be introduced as the main villain. Maybe a corrupt police officer who turns to the dark side. He could use his knowledge of the law and the city's security systems to commit crimes and frame the Miraculous heroes. He would be a formidable opponent as he has insider knowledge.

Title: 'The Rise of the Shadow Serpent'. In this fanfic, my villain OC is the Shadow Serpent. She was once a kind-hearted girl, but after being betrayed by those she trusted, she turned to the dark side. She uses her power to create illusions and chaos in Paris. Ladybug and Chat Noir face a tough battle as they try to figure out her motives and weaknesses.