Another possibility is a crossover with 'Star vs. the Forces of Evil'. Star and Wander could team up to fight some common enemy. Their different magical abilities and personalities would create an interesting dynamic. Star's more impulsive nature contrasted with Wander's eternal optimism could lead to both comical and heroic situations.
One idea could be a crossover with 'Steven Universe'. Wander and Sylvia could visit Beach City and interact with the Crystal Gems. They might get involved in one of the Gems' battles against a Homeworld threat and use their own unique skills to help out.
A 'Wander over Yonder' and 'Adventure Time' crossover would be cool too. Imagine Wander and Finn going on an adventure together. Finn could learn from Wander's positive and carefree attitude, while Wander might be intrigued by the magical and often strange Land of Ooo.
Another possibility is a crossover with "Star vs. the Forces of Evil". Star's magic wand and her somewhat chaotic personality along with Wander's positive energy would make for an interesting dynamic. They could work together to stop some sort of inter - dimensional threat that endangers both their worlds.
Maybe a fanfiction where Wander has lost his memory. Sylvia has to help him remember who he is while also protecting him from villains who want to take advantage of his vulnerable state. This could involve visiting old friends and places from Wander's past to jog his memory.
Perhaps a plot where the little bits create some sort of chaos in the universe, and Wander has to use his unique brand of kindness and problem - solving to set things right. He might have to convince the little bits that their actions are causing harm in a gentle way.
One popular 'Wander over Yonder' fanfiction story could be those that focus on Wander's further adventures in uncharted galaxies. For example, there might be a story where he discovers a planet full of musical creatures and has to use his charm and kindness to make peace between them and a group of noisy invaders. Another could be about Hater finally realizing the error of his ways through an encounter with a wise old being in a fanfic, which gives a different take on his character development.
If it's a crossover with 'My Little Pony: Friendship is Magic', Twilight Sparkle would be a great addition. Her studious and sometimes overly - serious nature would contrast well with Wander's laid - back approach. And the ponies' world of magic and friendship could be an interesting backdrop for Wander and Sylvia's adventures.
Well, in Wander Over Yonder human fanfiction, a frequent theme is dealing with the unknown. Since the show has a lot of strange and unique settings and creatures, humans in fanfics often have to face things they've never seen before. It could be a new form of energy or a really odd - looking alien. Another theme is about finding a place in a new world. When humans end up in the world of Wander Over Yonder, they struggle to fit in and find their purpose, which makes for some interesting stories.
One of the most interesting human characters is often the intrepid explorer type. They're the ones who are not afraid to venture into the unknown parts of the Wander Over Yonder universe. Another could be the scientist character, who is constantly trying to understand the strange alien technologies and phenomena. And then there's the everyman character, who represents the average human just trying to survive and make sense of this wild new world.
The black eye might also be used as a symbol in the fanfiction. It could represent a character's vulnerability or a mark of their past experiences. Some fanfictions might explore how the character overcomes this 'stigma' of the black eye and how it changes their perception of themselves or how others see them. There could also be themes of mystery, like how the character got the black eye in the first place if it's not immediately clear, and the story could revolve around uncovering that mystery.
Once you have the characters and the meeting situation sorted out, start planning the plot. It could be a simple adventure where they have to retrieve a lost item that has ended up in the other world, or it could be a more complex story about saving both worlds from a common enemy. Just make sure to keep the essence of Wander Over Yonder intact while incorporating elements from the other universe.
One popular theme is friendship. Characters like Wander and Sylvia often have their bond explored further in fan fiction. Another theme could be adventure in different parts of the universe they travel. For example, fan writers might create new planets with unique challenges for them to face.