Flash Crossover Glee Fanfic: What are some interesting plot ideas?

One idea could be to have the characters from Glee perform at a Central City event in the Flash universe. They could sing a song to boost the morale of the citizens during a time of crisis.

Another concept is that a villain from The Flash's world uses the power of music (inspired by the Glee club's performances) to create chaos. The Flash teams up with the Glee club to reverse the effects of the music - based villainy. The Glee kids could use their knowledge of harmony and rhythm to counter the negative musical energy, while the Flash uses his speed to stop the physical manifestations of the villain's attacks.

One idea could be that the characters from Glee find themselves in Central City during one of The Flash's battles. Maybe they get caught in the crossfire and The Flash has to save them while also dealing with the meta - human threat. For example, Rachel could be singing on the street when a meta - human causes chaos nearby.

One idea could be that a supernatural entity from the Supernatural world somehow ends up in Central City and starts causing chaos that only the Flash's speed can help contain. For example, a demon that can possess multiple people at once and the Flash has to use his speed to track down all the possessed bodies before the demon can complete a dark ritual.

One idea could be that Flash and Supergirl team up to stop a powerful alien villain who is causing chaos across both their cities. The villain could have the ability to manipulate time and space, which would make it a real challenge for the two heroes.

One idea could be Hermione using her magic to enhance the Glee Club's performances. For example, she could create amazing stage effects with spells. Another could be her helping the members of Glee with their studies, like tutoring them in difficult subjects. Maybe she could also introduce some wizarding world music to the Glee Club which has a completely different style and rhythm.

One idea could be a crossover with another superhero show where The Flash has to team up with their heroes to stop a multiverse - threatening villain. Maybe he teams up with Arrow and they have to combine their skills to take on a speedster from another dimension who can also turn invisible.

A plot could involve a character from Glee accidentally stumbling into the Starkid universe. For example, Rachel Berry could find herself in the middle of a Starkid rehearsal. She might initially be confused but then realizes she can learn a lot from their unique style of performing. This could lead to a series of comical and heartwarming interactions as she tries to fit in and contribute to their shows.

One plot idea could be that the Shadowhunters need to find a way to defeat a powerful demon that can only be weakened by a special type of music. So they seek out the Glee club. The Glee club members are hesitant at first but then realize the importance of their role. Another idea is that a spell gone wrong in the Shadowhunters' world sends some of their key characters to the Glee club's world. There, they have to adapt to high school life while also trying to find a way back. And the Glee club helps them blend in and in return, they learn about the Shadow World.

One idea could be a singing competition between the Glee club and the students from Victorious. They could meet at a national music event and initially be rivals, but then start to collaborate and learn from each other's styles. For example, the Glee club could teach the Victorious crew about more traditional musical theater numbers, while the Victorious students could introduce the Glee club to more modern pop and hip - hop influenced performances.