One popular theme is the 'forbidden love' aspect. Since Mal is from the Isle of the Lost and Ben is the king of Auradon, their relationship can be seen as something that goes against the norm in their world, which makes for an interesting and often explored theme.
One popular theme is their relationship development. Fans love to read about how their love grows and overcomes obstacles. Another is adventure, like them going on quests together. For example, in many fanfictions they might go on a magical adventure to save Auradon or the Isle of the Lost.
One common theme is love conquering all. Their relationship is a central part, and often they face obstacles like different upbringings or outside forces trying to break them apart, but their love prevails. For instance, in a lot of fanfictions, Mal's insecurities about being a former villain are soothed by Ben's love.
Love is a very common theme. Since Mal and Ben are a couple in the Descendants universe, many fanfictions focus on their relationship, whether it's about them falling in love, facing challenges in their relationship, or growing closer. For example, some stories might have them dealing with jealousy from other characters.
Love is a very common theme. Their relationship is central in the Descendants series, and fanfictions often expand on it. It could be about their first love, how they fell for each other despite their different backgrounds.
Romance is also a big theme. Some fanfictions imagine a romantic relationship between Mal and Audrey. This could involve a slow - burn kind of story where they gradually fall in love, or a more sudden realization of feelings in the midst of some big event in the Descendants world.
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.
There are many great fanfictions about Ben and Mal. Some might focus on their future together, like ruling Auradon. For example, in one fanfiction, they face a new threat that tests their relationship and leadership. They have to work together to overcome the challenges, which makes their bond even stronger.
The plot might involve Ben and Mal teasing a new student from the Isle of the Lost. They pretend to be very strict Auradonians and give the new student all these 'rules' that are really just made - up. The new student gets really confused at first. But as the story progresses, Ben and Mal reveal it was all a joke to make the new student feel welcome. They then become good friends and the new student joins in on their teasing games with the other students in Auradon.
One idea could be that Ben and Mal play a light - hearted prank on their friends in Auradon. They could tease them by pretending there's a new, super - strict rule coming from the palace. For example, they might say that all magic - using VKs have to have a curfew for their magic use only. Their friends would be all in a panic until Ben and Mal reveal it was just a joke.