Another plot could involve Anna getting a Miraculous. She could be a new hero in Paris, teaming up with Ladybug and Chat Noir. They might face a villain who has the ability to create eternal winter like in Frozen, and Anna's experience with dealing with Elsa's winter could come in handy. Also, the cultural differences between Arendelle and Paris could add some interesting twists to the story.
Perhaps the Miraculous Ladybug universe has a magical artifact that is related to Elsa's powers. A group of villains from both universes join forces to steal this artifact. Ladybug, Chat Noir, and their friends have to travel to Arendelle to seek Elsa's help in protecting the artifact. Along the way, they learn about each other's worlds and form new friendships.
One possible plot could be that Ladybug and Chat Noir are transported to the world of Frozen. There, they meet Elsa and Anna. Maybe they team up to fight a new villain that is causing chaos in both the Miraculous and Frozen universes. For example, a villain might be using the power of the Miraculous to freeze parts of Paris and also trying to take over Arendelle.
One idea could be a crossover with the DC universe. Ladybug and Cat Noir could team up with Superman to stop an akumatized Lex Luthor who has somehow gotten his hands on a Miraculous. Another plot could involve a crossover with the Harry Potter world. Maybe Hawk Moth tries to steal magic from Hogwarts, and Ladybug and Cat Noir have to work with Harry and his friends to stop him.
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.
One idea could be that Marinette and Adrien are cast in a school play as Romeo and Juliet. Their real - life superhero identities start to blend with the characters they're playing, and they find themselves in situations similar to the original story. For example, there are misunderstandings between them due to the interference of Hawk Moth, just like how the feud between the Montagues and Capulets caused problems for Romeo and Juliet.
Another idea is that the Phantom is akumatized. His love for Christine could be twisted into a desire for power and control over Paris. Ladybug and Chat Noir have to face this powerful akumatized Phantom. They might discover that the key to defeating him lies in understanding his tragic past and the love he once had. So, they team up with Christine to try and reach the Phantom's true self hidden beneath the akuma's influence.
Obviously, Ladybug and Chat Noir are the heroes in the Miraculous world, so they would be main characters. In Frozen, Elsa and Anna are the key figures. However, we might also see other characters like Tikki and Plagg from Miraculous having some interactions with the Frozen characters. For example, Tikki might be fascinated by Elsa's ice powers and try to understand how they work compared to the Miraculous powers.
One idea could be that the Reverser's powers are amplified and he starts reversing not just individual actions but entire relationships in Paris. So, Marinette and Adrien's unspoken bond is reversed, making them avoid each other at all costs. Another could be that the Reverser targets Ladybug's and Chat Noir's memories of their superhero identities, causing chaos as they try to figure out who they are again while still having to fight akumas. A third idea is that the Reverser somehow manages to reverse the concept of good and evil in Paris, making the akumas seem like the heroes and the heroes like the villains, and Ladybug and Chat Noir have to find a way to reverse it back.
One idea could be that the thief has a secret noble cause. Maybe they steal to return precious items to their rightful owners who were wronged in the past. For example, an artifact was stolen from a family long ago, and the thief is trying to make things right.
One idea could be that Zombizou actually has a hidden power within her zombie state that she can transfer to Ladybug or Chat Noir to help them defeat a new super - villain. For example, she might be able to make them invisible to the villain's special powers for a short time.
One idea could be a story where the child of Ladybug and Chat Noir discovers their parents' secret identities by accident. Maybe they find a hidden Miraculous box in the attic and start to figure out what it means.