It could be Alya. She's very curious and adventurous. Maybe she gets too close to some sort of werewolf lore or a werewolf in disguise while investigating for the Ladyblog. And then she gets bitten and turns into a werewolf. This would add a whole new layer of drama to her relationship with Marinette and the other characters.
Nino is also a possibility. He's always in the middle of things with his friends. He might be in the wrong place at the wrong time, like in an old, abandoned part of Paris where a werewolf lurks. Once he becomes a werewolf, he has to hide it from everyone, especially Alya, his girlfriend.
Even Gabriel Agreste could be the werewolf. It would be an interesting twist. He could be using his werewolf form to further his plans as Hawkmoth. Or perhaps the werewolf curse was something that happened to him long ago and is now intertwined with his search for the Miraculouses. This would make his character even more complex and menacing.
There's also a chance that it's a werewolf from another wizarding community that has come to Hogwarts and has fixated on Hermione. This werewolf could be on a mission, perhaps sent by a dark wizard, and Hermione just happens to be in his path, and he won't leave her alone as part of his orders.
One great 'miraculous werewolf fanfiction' is 'The Werewolf's Miraculous Mate'. It has an interesting plot where the werewolf character discovers his special bond with a miraculously gifted human. The story is full of adventure and the development of their relationship is really engaging.
Another place is FanFiction.net. There are many writers on this platform who create fanfiction for different fandoms. Although the quality may vary, you can surely find some 'miraculous werewolf fanfiction' by exploring different categories and using the search function. You might also find some on Wattpad, which is known for its wide range of fictional works, including fan - created content.
In this fanfiction wedding, not only their friends but also some of the heroes they've worked with in the past could be guests. Rena Rouge and Carapace would be there, having played important roles in many battles. Maybe even some of the one - time heroes like Pegasus or Viperion could show up. Ladybug's parents would be there with open arms, and Adrien's bodyguard could also be present, having seen Adrien grow up. And Paris itself could be considered a 'guest' in a way, as the city has been a big part of their lives and the reason for their superhero existence.
Another possibility could be a new character introduced specifically for the fanfiction. Maybe a powerful and charming hero from another city comes to Paris to help Ladybug and Chat Noir. He and Ladybug develop a connection, and he could end up being the father. This would create a lot of drama and new storylines, especially when it comes to how Chat Noir reacts to the situation.
In a Miraculous Ladybug sleepover fanfiction, the characters might have a lot of fun. They could play games like truth or dare, which could lead to some interesting revelations. For example, Marinette might accidentally let slip some of her feelings for Adrien.
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.
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.
There could be a fashion designer from a rival school who is jealous of Marinette's swimwear designs. This character could be a bit of a troublemaker and might unknowingly help Hawkmoth in his plans to steal Marinette's designs. But in the end, she could see the error of her ways and become a friend.
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.