Who might be responsible for Adrien's arrest in 'Adrien gets arrested fanfiction'?

It could be Harry Potter himself. He has been a victim of her tyranny and might finally find a way to expose her once and for all.

The Ministry of Magic could be responsible. They might be jealous of Dumbledore's power and popularity. They could see him as a threat to their own authority and come up with some false charges to arrest him. For example, they could claim he was hiding information about a dangerous dark wizard.

It could be an overzealous security guard. If Rachel was at a high - profile event and the security guard misinterpreted her actions as something threatening or against the rules, he could be the one to call the cops and get her arrested.

Maybe he was framed for a crime he didn't commit. Some jealous rival could have set him up to get him out of the way.

Adrien could meet other mysterious figures in the lair. It could be an old acquaintance of his father's who has been helping with his secret plans. Or perhaps he'll come across a captive who was being held by his father for some unknown reason.

Nathalie might be a character in these fanfictions too. Given her role in Adrien's life in the original series, she could be involved in the events leading up to his akumatization. Maybe she accidentally triggers his negative emotions. And then there's Gabriel, Adrien's father. His actions or lack of actions towards Adrien could be a major factor in Adrien getting akumatized. So, he could be a key character in the fanfiction, either as someone who realizes his mistake and tries to help or as someone who makes the situation worse.

It could be the wizarding authorities. If they discover that Vernon has been abusing Harry Potter all these years, they might decide to arrest him for child abuse. Even though they are in the wizarding world and Vernon is a Muggle, they could still have some jurisdiction over the well - being of a young wizard like Harry.

Marinette might also play a role. Even though she doesn't have direct knowledge of Adrien's family at first, she is very observant. She could notice something odd about Adrien's behavior when he starts to search for his father's wish and offer her help. Together, they could piece together the mystery from different clues around the city.

He might expect to see his relationship with Ladybug evolving. Maybe they end up together or have a stronger partnership.

It could be Ladybug. If Adrien turns villain, Ladybug would be the natural antagonist as she represents the good side. Their relationship would be completely flipped from what it was before. She would have to try to stop him from causing more harm, all while probably still having some feelings for the old Adrien.