You could write a fanfic about how the Mushroom War affected the magical elements in the Adventure Time world. Maybe the war disrupted the balance of magic, and certain characters are on a quest to restore it. They might encounter strange new magical creatures or phenomena that were born out of the chaos of the war.
One idea could be exploring the origin of the Mushroom War in more detail. Maybe there are some hidden causes or events that led to it. Another could be focusing on the characters' lives before the war and how it changed them. For example, how Finn's family was affected.
Well, a really interesting plot in Adventure Time Mushroom War fanfiction might be a story that focuses on the lost technology during the war. Maybe there were some super - advanced weapons or devices that got buried or lost. And a character discovers one and has to figure out how to use it without causing more chaos. Also, a plot could revolve around the relationships that were broken during the war and how they are slowly mended in the post - war world.
The Great Mushroom War in Adventure Time is a really interesting part of the story. It's this huge event that happened in the past. It was so destructive that it changed the world completely. The land was scarred, and new species emerged from the chaos. We know that there were probably different factions fighting, but we don't get all the details. There are hints that there was some sort of scientific and magical arms race that led to the war. The characters in the present day, like Finn and Jake, are living in a world that's still trying to recover from this cataclysmic event. They find old bunkers, strange weapons, and other things that are remnants of the pre - war civilization, which gives us little glimpses into what the world was like before the Great Mushroom War.
One interesting plot idea could be exploring the aftermath of the war from the perspective of a young survivor. They might be on a journey to find a rumored safe haven, facing various mutated creatures along the way.
One idea could be exploring the backstories of the characters involved in the Gum War. Maybe there are hidden alliances or personal vendettas that led to the war.
One idea could be that Breezy gets lost in the Land of Ooo and Finn and Jake have to help her find her way back home. Maybe she has a special mission that she needs to complete but can't without their help.
Finn and Jake would be obvious choices. Their courage and friendship could be put to the test in the harsh post - war world. They might be on a mission to help the survivors or to uncover the secrets of the war.
Finn is likely to be one of the main characters. He's a central figure in Adventure Time, so he'd probably play an important role in the fanfic related to the Great Mushroom War. Jake could also be there, as Finn's best friend.
One plot idea could be that Finn and Jake from Adventure Time end up in the Fallout wasteland. Finn, with his sword skills, could be on a quest to find a special artifact to get back to their own world. Jake, with his shape - shifting abilities, might help them survive against the various mutated creatures in the Fallout universe. Another idea is that the Vault - Tec technology in Fallout somehow merges with the magical elements of Adventure Time, creating strange new hybrids of mutants and magical beings.
One idea could be Finn and Jake swapping bodies. Finn in Jake's body might struggle with Jake's more laid - back and sometimes lazy attitude towards things like guarding the Tree Fort. He could be shocked at how comfortable Jake is just lying around. Another plot could involve Princess Bubblegum and Marceline swapping. Princess Bubblegum, in Marceline's body, has to deal with Marceline's vampire instincts like craving blood (in a non - too - gory way, of course). This could lead to some comical situations as she tries to resist her new urges while Marceline, in Princess Bubblegum's body, has to handle the responsibilities of ruling the Candy Kingdom and might be a bit too carefree for the Candy People's liking.