One interesting plot idea could be Jake and Marceline teaming up to explore a new, mysterious part of the Land of Ooo. Maybe they find an ancient relic that has the power to change the world. Another idea is that they get caught in a time - loop and have to figure out how to break it while dealing with their own personal issues.
One idea could be Marceline and Finn teaming up to explore a new and mysterious part of the Land of Ooo. They could encounter a powerful and ancient magic that they have to figure out how to control. Another plot could be Finn trying to help Marceline reconnect with a long - lost friend from her past. Maybe there's a feud between this friend and Marceline that Finn has to mediate.
One idea could be that PB accidentally creates a magical device that swaps their personalities. Marceline then has to deal with being super sweet and girly while PB tries to maintain her tough rocker image. It would lead to a lot of comical situations as they try to navigate their daily lives in each other's shoes.
Another plot could involve Jake Jr trying to prove herself to Finn and the other heroes. She could take on a difficult quest, like finding a rare ingredient to cure a sickness that has befallen the Candy Kingdom. This would show her determination and growth as a character. It could also involve her making new friends along the way who help her in unexpected ways.
Well, they could go on a quest to find a rare ingredient for a special cake that Jake wants to make. Along the way, they encounter various obstacles like a swamp full of gooey monsters or a forest with trees that can move. Also, a plot could be centered around Jake losing his stretching ability and Cake having to find a way to get it back for him. This would involve them visiting different parts of Ooo and asking for help from their friends.
Well, in some fanfictions, there could be a plot where Marceline's dad comes back to make amends for his past wrongdoings. He might try to reconnect with Marceline by helping her out in a tough situation, like when she's facing a really powerful enemy. It could also be interesting to see a story where Marceline's dad reveals some long - held family secrets that change how Marceline views herself and her powers.
A cool plot could be that Jake and Lady Rainicorn discover a hidden dimension. In this dimension, they find out that there are versions of themselves with different powers. They have to work together to find a way back home while also learning from these alternate versions. Or perhaps a story where they are invited to a royal ball in the Candy Kingdom but end up getting caught in a mystery involving a missing jewel. They then use their unique skills to solve the mystery.
A really interesting plot could be set in an alternate dimension where Ice King is a normal king and Marceline is a human. They meet in this new world and have to figure out how to get back to their own world while also dealing with the new relationships and challenges this world presents. They might discover that their bond is stronger than they thought, even in these different forms.
Another interesting fanfic idea is that Marceline loses her vampiric powers and Marshall Lee has to help her adapt to a more 'human' or at least non - vampiric life. This would lead to a lot of character development as Marceline struggles with her new identity and Marshall Lee learns more about her true self beyond her powers.
One interesting Marceline x Jake fanfiction could be about their adventures in a magical forest together. They might discover a new kind of music that Marceline can incorporate into her songs, and Jake uses his shape - shifting abilities to help them navigate the forest's tricky paths.
One interesting fanfiction could be about Marceline and Bubblegum going on a quest together to save the Candy Kingdom from a new, mysterious threat. In this story, their relationship could be explored more deeply as they face challenges side by side.