One idea could be exploring Robustus's backstory in more detail. Maybe he had a difficult past that led him to become a villain. Another plot could involve him forming an unexpected alliance with the heroes. For example, a common enemy forces them to work together. And a third idea is a story where Robustus tries to reform and find a new purpose in life.
Well, a really interesting plot could be centered around Robustus getting a taste of what it's like to be a hero. He could accidentally gain a new power or be put in a situation where he has to protect someone. This would be a great character development opportunity for him. Also, a plot where he falls in love with a civilian and has to balance his villainous ways with his new - found feelings could be fascinating. Another plot could be that he discovers a hidden power within himself that could either make him a greater threat or a potential ally to Ladybug and Cat Noir.
I think Ladybug would be an interesting character to pair with Robustus. Their opposing natures could lead to some great conflict and character development. Another good option could be Cat Noir. His carefree attitude could contrast well with Robustus's more serious nature. And then there's Alya. As a journalist, she could be curious about Robustus and try to understand him, which could create an interesting dynamic.
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 Multimouse having to team up with an unexpected ally, like a villain who has a change of heart for a short time. Another could be Multimouse getting lost in an alternate dimension and having to find her way back while facing new challenges.
One idea could be Ladybug and Chat Noir having a heart - to - heart conversation in bed after a particularly tough battle. They could share their fears and insecurities that they usually hide behind their superhero personas.
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.
For a Miraculous Ladybug class fanfiction, a plot about a cursed object in the classroom could be interesting. The object spreads negative energy, causing the students to fight and argue more. Ladybug and Chat Noir suspect that it's an akuma - related thing, but they can't find the akuma. As they investigate, they discover that it's actually an ancient cursed item that was accidentally brought into the class. They have to find a way to break the curse without revealing their identities, and also deal with the fact that their classmates' relationships are falling apart because of the curse.
Maybe there's a werewolf akuma. Hawkmoth takes advantage of an already existing werewolf in the city and akumatizes it. This werewolf - akuma has enhanced powers and is causing chaos. Ladybug and Chat Noir must figure out how to defeat it. They might need to discover the true identity of the werewolf to break the akuma's hold. It could be a person who was bitten recently and is struggling to control their new form.
Another plot could be that a crime wave hits Paris, and all the evidence points to Chat Noir as the perpetrator. Ladybug is torn between believing in her partner and the mounting evidence against him. She has to dig deeper into the case to find the real criminal who is framing Chat Noir and clear his name.
One idea could be that Ladybug and Chat Noir are sent to space on a mission to stop an alien villain who is stealing energy from planets. They have to adapt to zero - gravity combat and use their powers in new ways. For example, Ladybug's yo - yo could be used to grapple onto spaceships.
A plot could involve the whole gang from Miraculous Ladybug going camping together. Marinette could be worried about Tikki being discovered in the wild. Meanwhile, Adrien, as Chat Noir, tries to impress Marinette. And during the camping trip, there's a mystery about a strange light in the forest that turns out to be related to an ancient Miraculous. So they all have to work together to figure it out.