An engaging plot for this fanfiction can be created by making the characters face moral dilemmas. For instance, if Marceline has to choose between saving her friends or winning the Danganronpa game to escape a dangerous situation. Incorporate the art style of Adventure Time into the Danganronpa - ish story. This can give a fresh look to the whole concept. Another important aspect is pacing. Don't rush the story. Let the readers get to know the characters and the situation they are in. For example, if you introduce a new character like a Danganronpa - style villain in the Adventure Time universe, build up their backstory and motives slowly so that the readers are fully invested when the big revelations happen.
To write an engaging plot for an Adventure Time Danganronpa fanfiction, first, combine the unique elements of both. Take the wacky and colorful world of Adventure Time and introduce the mystery and life - or - death situations from Danganronpa. For example, you could have Finn and Jake end up in the Danganronpa world. Create complex characters by mixing the traits of Adventure Time characters with Danganronpa's diverse personalities. Make sure there are lots of plot twists, like a seemingly innocent character turning out to be the mastermind. Build suspense gradually, for instance, by slowly revealing the rules of the deadly game in the fanfiction world. And don't forget to add some humor from Adventure Time to lighten the mood in the midst of the Danganronpa - style drama.
Well, start with a great premise. Maybe there's a crossover event that forces the Adventure Time gang to participate in the Danganronpa killing game. You need to focus on the relationships between characters. If Princess Bubblegum was in Danganronpa, how would she interact with the other students? Think about her scientific mind and how it could be used to solve the mysteries or, on the other hand, create new problems. Also, use the setting to your advantage. The strange and wonderful landscapes of Adventure Time can provide interesting backdrops for the Danganronpa - like events. For example, a trial could take place in the Candy Kingdom. This will make your fanfiction stand out and be more engaging.