What are some interesting ideas for 'Star vs the Forces of Evil crossover fanfiction'?

One interesting idea could be exploring a darker side of Marco's character. Maybe he has some hidden powers or motives that are revealed in the fanfiction. Another idea could be his relationships with other characters in this 'evil' scenario. For example, how does his friendship with Star change when he takes on this new, darker persona.

One interesting concept could be characters from different universes within the fanfiction meeting and interacting. For example, Star from 'Star vs the Forces of Evil' might meet characters from other popular shows. This can lead to unique storylines and character developments. Another concept could be the combination of different magical elements from the show and the crossovers. It can create new powers and challenges for the characters.

A great crossover idea is to put Star in a situation where she has to prove herself to the Avengers. Maybe she accidentally lands in the middle of an Avengers battle and they initially think she's a threat. But then she shows them her skills and they work together. Also, imagine Marco being friends with Spider - Man. They could exchange stories about their adventures and help each other out in their respective battles.

One idea could be creating an OC who is a hybrid of different magical species in the 'Star vs the Forces of Evil' universe. For example, part Mewman and part monster. This OC could struggle with acceptance from both sides. Another idea is an OC who has a unique magic ability that no one has seen before, like the power to control time on a small scale. This could lead to all sorts of adventures and challenges as they try to master it without causing chaos.

Another interesting plot could be Meteora forming an unlikely alliance. For example, she teams up with a group of misfits who are also on a quest for something. Together, they face various challenges and in the process, Meteora learns about friendship and trust.

One idea could be exploring an alternate universe where Star and Marco's roles are reversed. Another could be a fanfic that focuses on the backstory of a minor character like Pony Head. Or perhaps a story where the forces of evil have a more sympathetic origin.

Well, a cool plot might involve a mermaid princess in the Star vs the Forces of Evil world who is in love with Marco. Star helps her to win Marco's heart in exchange for some magical mermaid artifact that can help Star in her fight against the forces of evil. Or perhaps there's a mermaid coven that has been cursed by Ludo's family long ago, and Star has to break the curse to gain their allegiance against the ever - growing forces of evil.

Perhaps in the fanfiction, Toffee's memories are transferred into Star's mind. Star then has to deal with not only her own thoughts but also Toffee's memories and emotions. This could lead to her making decisions that are influenced by Toffee, which confuses her friends and family. She has to find a way to separate Toffee's memories from her own without losing her own identity in the process.

Perhaps a plot where the forces of evil from both universes join together. Ben and Star have to form an alliance with their respective friends and family. They must learn about each other's powers and strategies to defeat this combined evil. Ben might teach Star about his alien tech, and Star could show Ben how to use magic in combat.

One idea could be that Eclipsa discovers a new, hidden power within herself that gives her an edge against the forces of evil. Maybe it's a long - lost spell from her ancient lineage. Another could be a team - up between Eclipsa and some unexpected allies from different realms to fight the forces of evil.