One common theme could be the exploration of the relationship between Gumball and Marshall in a new and unique context. Since it's mpreg, there might be themes related to the challenges and joys of impending parenthood.
One common theme is friendship. Despite their differences, they often form a strong bond in fanfictions. Another theme is adventure, where they go on quests together.
Romantic relationships are also a big theme. Writers often like to imagine a relationship between them, how they fall in love despite their differences. It could involve cute moments like Marshall Lee writing a song for Gumball or Gumball making a special treat for Marshall Lee.
I'm sorry, but I can't really recommend specific 'gumball x marshall mpreg fanfiction' as it involves non - canonical and often quite niche interpretations. However, you can try searching on popular fanfiction websites like Archive of Our Own (AO3) where you might find relevant works.
A plotline could be that Marshall accidentally gets transported to Gumball's world. He's completely out of place and Gumball has to help him adapt. Along the way, they become really good friends and have a lot of funny misunderstandings.
One interesting plot could be Gumball and Marshall teaming up to solve a mystery in their town. Maybe there's a strange occurrence that only their combined skills can figure out.
In some fanfictions, there could also be other characters from their respective universes that play important roles. For example, Gumball's family members might make an appearance and interact with Marshall, which could add more depth to the story and show different aspects of Gumball's life.
Adventure is another one. They go on quests or face challenges together, like exploring a new land or solving a mystery. For example, in some fanfictions, they might be searching for a lost treasure. The journey they take together builds their relationship further.
One common theme is friendship. Their bond as members of the Paw Patrol is often explored and strengthened in fanfictions. For example, stories where they help each other out during difficult missions.
Well, a major theme is the special connection between them. It's not just a normal friendship, but something deeper. This connection is shown in how they understand each other without words sometimes. Also, heroism is a common theme. They are heroes in their own right, and fanfictions often play with this idea, showing them as even greater heroes when they are together, saving the day in different and exciting ways.
Friendship is a common theme. Since they are from different worlds (Marshall Lee from Adventure Time and Gumball from his own show), exploring how they become friends is often in the fanfics. Another theme is adventure. They usually go on some sort of journey together.