I'm not sure specifically as I haven't read this particular 'glee' fanfiction. But generally, it might be about a situation where a character is in a difficult or trapped situation, similar to how a pig might be stuck, within the world of 'glee' with all its drama, relationships and musical elements.
I don't know for sure as I haven't read it. But it could be the main characters from 'glee' like Rachel, Finn, Kurt, or Santana. Maybe it focuses on one of them in a'stuck' situation.
It's probably not a common plot. Glee fanfictions usually revolve around the main aspects of the show such as the competition among the glee clubs, the romances between the characters, and their struggles with self - identity. While this phrase could be part of a story, it's not likely to be the central plot that most fanfictions are built around.
Yes, some shadowhunters might like to watch Glee fanfiction. Glee has a large and diverse fan base, and its fanfiction can cover a wide range of interesting stories. If a shadowhunter is also a fan of Glee, they may be interested in exploring the fan - created stories in the fanfiction world.
In a Glee and Avengers crossover, there could be a plot where the villains from the Avengers' world target the Glee club because they see their unity and positive energy as a threat. The Avengers would have to protect them. Finn could be inspired by Captain America's leadership and try to step up as a leader in the Glee club. And the Avengers might be entertained by the Glee club's musical numbers during their down time.
It would be a wild adventure. You might find yourself in a situation where you have to use your knowledge of the Mass Effect lore to survive. Maybe you'd join a crew on a spaceship and go on quests to save the galaxy. However, you'd also have to deal with the fact that this is a world created by fans, so there could be unexpected twists and turns that deviate from the original game's story. It could be a chance to rewrite parts of the Mass Effect story in your own way, but also a struggle to fit into a world that has its own set of rules.
It is common in the sense that fanfiction has become a huge part of fan culture in general. For 'glee' fans specifically, they might be missing the show and the characters. Reading fanfiction can be like getting a new episode or a new story arc. It also satisfies their curiosity about what could have happened in different scenarios in the 'glee' world, so it's a popular activity among 'glee' enthusiasts.
It could be really interesting. Harry could bring his magical elements into the Glee club. Maybe he uses magic to create amazing stage effects during their performances. For example, he could make the set change magically or add some floating musical notes with a spell.
A 'glee avengers crossover fanfiction' might involve the characters' unique abilities combining in unexpected ways. For example, Iron Man could use his tech to enhance the Glee club's stage effects. The Glee characters could introduce the Avengers to the power of music and performance to boost their morale. It could also be a story about how the two groups learn from each other's values, like the Avengers' sense of justice and the Glee club's unity through music.
It could be really interesting. Imagine the characters from Glee suddenly thrust into the brutal world of the Hunger Games. The singers and performers from Glee would have to use their wits and any hidden survival skills. For example, Rachel Berry might try to use her show - stopping voice to gain sponsors, much like the tributes in the Hunger Games do to get supplies. And the different cliques in Glee could form alliances similar to the district alliances in the Hunger Games.