Definitely Tikki and Plagg. These Kwamis are essential to the Miraculous universe. Their interactions with Cat Noir and Ladybug, as well as their own little quirks and personalities, can make for really fun fanfiction. Additionally, Sabrina, Chloe's sidekick, can be an interesting character to include. She could have her own story of breaking free from Chloe's control or getting involved in the hero - villain drama in some unexpected way.
There are fanfictions where Cataclysm has unexpected side effects. Maybe after using it, Chat Noir starts to lose his powers gradually and has to find a way to reverse it while still fighting Hawkmoth. This creates a lot of tension and interesting plot twists.
One idea could be that Cat Noir and Ladybug get transported to an alternate Paris where the roles of heroes and villains are reversed. They have to figure out how to adapt and set things right. Another could be a time - travel plot where they go back in time to prevent Hawkmoth from ever getting his hands on the Miraculous in the first place. And a third idea is that there is a new villain who can manipulate emotions, and Cat Noir and Ladybug have to not only fight the physical battles but also the emotional turmoil this villain causes among the citizens.
There are some Miraculous Ladybug fan communities on Tumblr. People often share and recommend fanfictions there. You can search for tags like 'Cat Noir Ladybug Miraculous fanfiction' and you might find some great links to stories where Cat Noir asks for Ladybug's Miraculous. Some fans also post their own works directly on Tumblr.
There's a fanfiction called 'A Miraculous Exchange'. Cat Noir is in a real bind during a battle and asks Ladybug for her Miraculous. She hesitantly gives it to him. He then discovers new powers within the combined Miraculous that he didn't expect. This story delves into the idea of teamwork and trust between the two heroes on a deeper level.
Obviously, their best friends like Alya and Nino would be there. Alya could be Ladybug's maid of honor, and Nino could be Cat Noir's best man. Also, all the other superheroes they've worked with in Paris would be invited. And of course, their families, if their identities were revealed by then. Maybe even some of the citizens of Paris who have been saved by them over the years would show up to celebrate this special occasion.
Ladybug would be extremely shocked and heartbroken. She has always seen Cat Noir as her partner and friend, and to see him akumatized would be like losing a part of herself. She would be determined to save him at all costs, trying to find a way to communicate with him beneath the akuma's influence.
A third writer to check out is [Yet Another Writer's Name]. Their fanfictions about Cataclysm in the Miraculous Ladybug universe are known for their detailed character development. They show how Chat Noir's use of Cataclysm affects not only the villains but also his relationships with other characters like Ladybug and his civilian friends.
One possible fanfiction could involve Chat Noir being akumatized after a major argument with Ladybug. Maybe he feels constantly overshadowed or unappreciated. The akuma could enhance his negative feelings, making him more aggressive and less in control. His powers might become distorted, and he could start causing chaos in Paris. Ladybug would then have to find a way to reach out to the real Chat Noir inside the akumatized form and purify the akuma.
She would also be very determined to bring him back to the good side. Ladybug might search for a way to break whatever spell or influence has made Chat Noir evil. She could look for a special power - perhaps from another Miraculous or a magical item - that can reverse the change. And in the meantime, she has to be careful not to get hurt by Chat Noir while still trying to protect Paris.