Some common themes could be Marceline's struggle with her vampiric nature while being sick. It might show how her friends in the Adventure Time world try to take care of her. For example, Finn and Jake could be there to cheer her up or find a cure for her illness.
Often, there can be a theme of vulnerability. Marceline is usually a tough character, but when she's sick, she becomes vulnerable. This can lead to different relationships in the fanfic developing in new ways. Her relationship with Princess Bubblegum, for instance, might change as PB tries to help Marceline get better, showing a softer side to their complex relationship.
Another theme could be Marceline's past experiences coming back to haunt her while she's sick. Maybe memories of her difficult upbringing or past battles resurface, and she has to deal with them while also dealing with being ill. This can add an interesting layer of depth to the fanfic.
Adventure is a major theme too. Since they are in the world of Adventure Time, they go on quests and have escapades. This theme allows for a lot of action and exploration in the fanfics. And there's also the theme of trust. As their relationship develops, they learn to trust each other more and more, which is a key part of their story.
One great 'Adventure Time' Marceline fanfic could be 'Marceline's Melody'. It delves into her past, exploring her relationship with her father and how it shaped her into the vampire she is. It's filled with beautiful descriptions of the Land of Ooo and Marceline's unique perspective on life.
One common theme is friendship. Finn and Marceline have a unique friendship that often gets explored in fanfiction. They come from different backgrounds, Finn being a human hero and Marceline a vampire, and how they bridge those differences in their friendship is a popular theme. Another is adventure. Since they live in the Land of Ooo, they often go on wild adventures together in these stories.
One common theme could be Finn getting embarrassed in front of his friends. For example, he might trip and fall while trying to show off a new skill. Another theme could be his romantic embarrassments, like when he tries to ask a girl out and stumbles over his words.
There are fanfics where the Lumpy Space Princess gets sick. Since she's so self - centered, it could be really funny to see how she demands everyone to take care of her. And in some sick fanfics, it's not just a physical illness. There could be a 'sickness' that affects the magic in the Land of Ooo. Finn and his friends then have to go on a quest to find a cure, which makes for an exciting adventure - filled fanfic.
Including other Adventure Time characters in an unexpected way can make it engaging. Like having Ice King try to 'cure' Marceline with his strange magic, which could lead to comical or heart - warming moments. Also, exploring Marceline's emotions deeply, like her fear of being weak or her frustration with the illness, can draw readers in.
One common theme is the exploration of their past. In many Marceline x Bubblegum fanfics, the authors look at how their past experiences, like Marceline's vampire nature and Bubblegum's role as a princess, have influenced their relationship. Also, the theme of redemption sometimes shows up, especially when it comes to Marceline's more wild side and how Bubblegum helps her find a more positive path. Growth is also a common theme, as they both grow as individuals within the context of their relationship.
One common theme could be the exploration of America's vulnerability during sickness. It might show how other characters in the Countryhumans universe react to a sick America. For example, they could offer help or show different levels of concern. Another theme could be the internal struggle within America itself, like dealing with the weakness that sickness brings while still trying to maintain its usual image of strength.
One great fanfic could be 'The Adventure Beyond the Nightosphere'. It shows Finn and Marceline going on an unexpected journey into Marceline's home realm, facing strange creatures and solving a mystery that endangers both their worlds. It has a great blend of action and their unique friendship dynamic.
There's also 'The Unspoken Connection'. This fanfic delves deep into their past and how their friendship/relationship has evolved over time. It has some really touching moments that fans of the two characters will love. It also includes some great descriptions of the Adventure Time world that add to the overall atmosphere.