A more light - hearted idea could be that Tikki and Plagg get curious about the spirit world in the Avatar universe. They drag their holders, Marinette and Adrien, into an adventure in the spirit world. There, they meet various spirits that are similar to kwamis in some ways, and they have to solve a mystery that is threatening the balance between the spirit world and the human world.
One idea could be a story where the Peacock Miraculous has a unique malfunction that causes it to create unexpected akumas. For example, instead of creating the usual villains, it creates akumas that have the power to spread positive emotions but in a chaotic way that still disrupts Paris. Another idea is a fanfiction where the holder of the Peacock Miraculous has to team up with Ladybug and Chat Noir to fight against an ancient evil that is specifically drawn to the power of the Peacock. This could involve exploring the history of the Miraculous and its connection to this new threat.
A crossover with the world of Sailor Moon would also be cool. The Miraculous holders could meet the Sailor Scouts. They could exchange their powers and fighting techniques. For example, Ladybug could show Sailor Moon how to use her yoyo in a more strategic way, and Sailor Moon could teach Ladybug about the power of love and friendship in her battles.
One idea could be a dance competition in Paris where Marinette and Adrien are secretly the superheroes. They use their super - agility and grace in the dance, which surprises everyone. Their opponents think they are just normal kids but they show extraordinary skills. Maybe there could be a villain who tries to disrupt the competition by using some dark magic related to the dance floor.
One idea could be a masquerade - themed party. All the characters from the Miraculous Ladybug universe could show up in elaborate masks and costumes. It would add an air of mystery and elegance to the party.
Well, you could write a fanfiction where Marinette, as Ladybug, discovers a hidden car in her family's garage that turns out to be an ancient vehicle with a connection to the Miraculous. She then has to figure out how to use it to fight Hawkmoth. It could involve some cool tech - like the car being able to transform or have stealth mode.
You could also write a fanfiction where the magic in the Miraculous Ladybug universe somehow gets intertwined with the magic in the Descendants' universe. Maybe the Miraculous themselves are affected by the dark magic from the Isle of the Lost, causing unexpected powers and challenges for Ladybug and Chat Noir as they deal with this new threat while also trying to keep their identities secret.
You could write a fanfiction where the Miraculous powers are used in unexpected ways. For example, instead of just fighting akumas, they are used to solve everyday problems in Paris. This would add a new dimension to the story and show the versatility of the Miraculous. Also, exploring the relationships between the characters outside of their superhero duties can make for an interesting fanfic. Maybe a story about Marinette and Alya's friendship growing stronger through a non - superhero - related adventure.
You could write a fanfiction where there are new Miraculous holders. Imagine a character who discovers a long - lost Miraculous and has to learn how to use it. This new character could team up with Ladybug and Chat Noir, or they could start out as an antagonist because they misuse the power at first. Their journey of learning to be a true hero or villain could be really engaging.
Well, you could have a fanfiction where the umbrella is a key element in a time - traveling adventure. For example, Ladybug and Chat Noir find an old umbrella that transports them to a different era in Paris' history. Or perhaps an akumatized villain uses umbrellas to spread his or her power, and Ladybug and Chat Noir have to find a way to counter this by using the unique properties of Ladybug's own umbrella. Also, it could be that the umbrella is a portal to another dimension, leading to a whole new set of challenges and adventures for our heroes.
One idea could be to explore what would happen if the Miraculous powers were transferred to animals. For example, a cat could become the holder of the Cat Miraculous and have to save Paris in a very different way than Chat Noir. Another idea is to create a story where the animal kwamis interact more directly with regular animals, like Tikki befriending a group of ladybugs and teaching them to help in small ways.