I read a fanfiction once where Marinette accidentally turns into a mermaid during a fight with an akuma. It was really interesting because she had to figure out how to use her new mermaid abilities while still fighting the akuma. Her tail was this beautiful blue - green color, and she could swim super fast. The story had a lot of action and some really cute moments between her and Chat Noir when he was trying to help her get used to her new form.
There's a fanfiction where Marinette is a mermaid princess in a parallel world. In this world, Chat Noir is also a merman. They meet when Marinette is exploring the ocean around her mermaid kingdom. Their relationship develops in a different way compared to their normal selves in the Miraculous Ladybug world. Here, they have to deal with underwater villains and protect the mermaid and merman kingdoms together. It's a really cool take on the characters.
One great fanfiction could be where Marinette discovers she has mermaid powers while still being Ladybug. It might start with her finding a strange shell that gives her the ability to transform into a mermaid. In the story, she could use her mermaid form to access new parts of Paris that are underwater, like hidden caves. This would add an exciting new dimension to her adventures as Ladybug and also her relationship with Adrien. Maybe she has to keep her mermaid identity a secret from him at first, which would create some interesting drama.
One great fanfiction could be about Marinette getting the Peacock Miraculous in a unique situation. For example, in a world where all the Miraculouses are scrambled among the characters, Marinette discovers the Peacock Miraculous while on a solo adventure. She has to figure out how to use its powers, which are different from the Ladybug Miraculous she's used to. This could lead to some really interesting character development as she tries to master a new set of abilities.
I really like 'The Hidden Bond'. In this fanfiction, Marinette discovers a new side to Cat Noir that she hadn't seen before. It's full of cute moments and some really well - written dialogue. It also has an interesting plot that keeps you hooked from start to finish.
There is this fanfic named 'Discovery of a Lifetime'. Marinette discovers that there is a parallel Miraculous world that is linked to her own. This discovery leads her on a journey to explore this new world and find out how it relates to her role as Ladybug. The story has a lot of world - building and Marinette's character development is really interesting throughout the story.
A common trope is the 'underwater adventure' trope. The fanfiction often takes Marinette on exciting adventures underwater. She might explore lost underwater cities, find hidden treasures, or encounter ancient sea monsters. This allows for a lot of world - building and showcases the beauty and danger of the underwater world. Also, the 'fish - out - of - water' (pun intended) trope is used when Marinette has to adjust to her new mermaid form and the underwater lifestyle.
There's also 'Marinette's Hidden Talents'. In this fanfic, Adrien discovers some unique skills that Marinette has been hiding. It's a really interesting take as it builds on their characters and the bond between them. It has a lot of cute moments and a bit of mystery too.
One great Marinette x OC fanfiction is 'A New Hero in Paris'. In this story, the OC has a unique power that complements Marinette's Ladybug abilities. The interactions between them are really well - written, starting from initial misunderstandings to a deep friendship and potential for more. It shows how the OC fits into the Miraculous Ladybug world and the challenges they face together.
One great fanfiction could be 'Marinette's Unbound Locks' where she lets her hair down during a special moment at a school dance. It beautifully describes how her long hair frames her face and adds to her charm as she shares a dance with Adrien.
One possible scenario could be that Marinette gets injured during a fight as Ladybug and is rushed to the hospital. In the fanfiction, her friends might come to visit her, and there could be some sweet moments between her and Adrien as he's worried about her. Maybe she has to keep her identity a secret even while in the hospital, which adds an extra layer of tension.
There's also 'The Luka - Marinette Connection'. In this fanfiction, the connection between Luka and Marinette is explored on a deeper level. It starts with Luka noticing Marinette's little quirks and how she tries to hide her feelings. As the story progresses, they start to open up to each other more. The author creates a really engaging story by adding in some mystery elements related to the Miraculous and how it might affect their relationship.
One possible fanfiction could be about Marinette transforming into a mouse - themed Miraculous holder. Maybe she discovers a new mouse - themed Miraculous in a hidden part of Paris. This could lead to her having new powers like super - speed and the ability to fit into small spaces. She could use these powers to outwit Hawk Moth's akumas in a really unique way, and her relationship with Adrien might also take an interesting turn as she tries to keep her new identity a secret from him.