Well, a plot could revolve around Marco and Star dealing with the reactions of their friends and family to the pregnancy. Some might be overjoyed, while others could be worried about the challenges ahead, like how they'll balance their duties and raising a child in a world full of magical threats.
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.
A great plot idea could be that Eclipsa discovers a hidden power within herself that is both a blessing and a curse. She has to figure out how to control it while also dealing with the politics of Mewni. Another could be a time - travel fanfiction where Eclipsa goes back to key moments in Mewni's history to change things for the better. And one more idea is that Eclipsa starts a school for different kinds of magic, which causes a stir among the traditional magic users in Mewni.
One interesting plot idea could be that Toffee Star, having some hidden powers, teams up with an unexpected character from The Forces of Evil. Maybe a character who was once an enemy but now they have a common goal. For example, they both want to stop a new, greater evil that is emerging in their world. This could lead to a lot of character development as they learn to trust each other.
Another interesting plot could be about a character who discovers an unexpected side - effect of the 'Cleaved' event. Maybe there are new powers emerging or a hidden danger that only they can sense, and they have to convince others to take action.
One idea could be that Star discovers a magical gaming console in the Magic Realm. This console has games that are actually portals to different dimensions. She and Marco could team up to complete the levels in the games to save these dimensions from an evil force that is spreading through the gaming portals.
Well, perhaps a plot where hypnosis is used to make the characters switch personalities. For example, Star becomes very timid and cautious instead of her bold self, and Marco becomes overly confident. They then have to navigate their daily challenges in this reversed state until they can break the hypnosis. This would lead to a lot of comical and also some heartfelt moments as they learn about themselves and each other in new ways.
Another plot could involve Tom having to face his own family's past actions that are now affecting Star and the forces of evil. He has to make amends and find a way to stop his family's legacy from causing more harm, which would put him in a difficult position as he tries to balance his loyalty to his family and his love for Star.