Maybe in the fanfic, Mal accidentally falls into the enchanted lake and it sends her to an alternate dimension. Ben has to find a way to enter that dimension and bring her back, facing many challenges along the way. For example, he might have to solve riddles given by the guardians of the lake.
One idea could be that Ben discovers a hidden power within the enchanted lake that can transform him into a mythical creature. This new form gives him unique abilities to protect the forest around the lake.
A possible plot could be that an ancient evil is lurking beneath the enchanted lake. Ben and Mal sense this and they team up with other characters. They must use the magic of the lake itself to defeat the evil. The lake could have different zones with various magical properties that they need to explore and understand to succeed.
It could be a dark sorcerer who wants to drain the magic from the enchanted lake for his own evil purposes. He might be jealous of the good magic that Ben and Mal possess and try to stop them from protecting the lake.
A common theme is discovery. Ben often discovers new things about the enchanted lake, like hidden caves or magical creatures. Another theme is adventure as he usually has some sort of exciting journey around the lake.
One idea could be that Mal struggles with her new role as Ben's girlfriend and future queen. She might feel pressured by the expectations of Auradon society. Another could be a story where an old enemy from the Isle of the Lost tries to break them apart by causing misunderstandings between Mal and Ben.
One idea could be Ben trying to introduce more modern ideas to the Isle of the Lost while Mal is hesitant as she fears it might disrupt the fragile peace. For example, he wants to start a school exchange program but Mal is worried about old grudges resurfacing.
One idea could be exploring how Ben and Mal's family deals with a new magical threat to Auradon. Maybe an old enemy resurfaces and they have to combine their unique skills and powers to protect their kingdom.
Well, there is a fanfic called 'Ben's Journey in the Enchanted Lake'. In this story, Ben discovers some hidden secrets of the lake. The author does a great job in describing the magical elements of the lake. It's a really immersive read.
Well, a possible plot for the Ben and Mal baby fanfiction could be centered around the baby's first birthday. All of Auradon is invited, but an unexpected guest shows up, someone from Mal's past who isn't too happy about the union between Ben and Mal. This person tries to cast a spell on the baby, but the combined love and magic of Ben and Mal protect their child. Also, the baby could start showing signs of being able to communicate with animals, which is a big deal in Auradon as it might mean a new era of harmony between humans and animals.
One idea could be that Mal and Ben face challenges in their relationship due to the unexpected pregnancy. Their kingdoms might have different reactions, with some being supportive and others worried about the future of the united kingdoms. They have to work together to prove that they can handle this new chapter while also dealing with any internal doubts.
A cool fanfiction could be Mal and Ben swapping powers for a day. This would lead to all sorts of comical and also challenging situations. For instance, Mal would have to deal with the responsibilities of being a king - like making important decisions in court - while having Ben's more 'goody - two - shoes' power. And Ben would be on the Isle of the Lost, trying to use Mal's magic in a place where it's not always welcome. Or a story where they go on a secret adventure away from Auradon, just the two of them, and discover a hidden land that has its own set of rules and magic, and they have to adapt quickly to survive.
You could write a fanfiction where Ben and Mal get transported to an alternate dimension. In this dimension, their roles are reversed. Mal is the one in charge of Auradon and Ben is from the Isle of the Lost. They have to figure out how to get back to their own world while also learning about each other in this new dynamic.