The relationship with Adrien is a huge theme. It could be about how they navigate their relationship when this big change occurs. Some fanfictions show them having to grow up quickly and become more responsible for each other and the baby. It also might explore how their identities as Ladybug and Chat Noir play into their new family situation.
One common theme is the exploration of their unrequited love. In the show, Marinette has a crush on Adrien, but in fanfictions with Luka, she may start to realize her feelings for him. Another theme is the power of music. Since Luka is associated with music, it often plays a role in bringing them closer, like Luka writing a song for Marinette.
One common theme is the exploration of unrequited love. Sometimes Marinette is still pining for Adrien while Luka is there loving her silently. Another theme is the power of music in their relationship, as Luka is a musician. It often serves as a bond between them.
One common theme could be Marinette's struggle with her anger in relation to her love for Adrien. Maybe she gets angry when she sees him with other girls out of jealousy. Another theme might be her anger towards Hawk Moth and his villains, as she tries to protect Paris in her Ladybug form. Also, it could explore how her anger affects her friendships, like with Alya, when she's too frustrated to confide in her.
One common theme is the 'will - they - won't - they' situation. Since Marinette is so shy and Adrien is a bit clueless about her feelings, a lot of fanfics play around with this dynamic.
A common opponent is Chloe when she gets akumatized. In fanfiction, their battles can be more intense and personal. Marinette, as Ladybug, has to deal with Chloe's over - the - top attacks and her mean - spirited nature while trying to purify the akuma.
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 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.
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.
In Miraculous Ladybug fanfiction, Marinette in a bikini could be part of a beach - themed story. Maybe she's on vacation with her friends. It could be a fun and light - hearted scenario where she shows off her confidence and style while enjoying the sun and sand.