Well, they might be really confused at first. Since they are from an earlier time in the Harry Potter universe, the events and characters in the 'Goblet of Fire' fanfiction would be quite new to them. They might be shocked by some of the modern interpretations of magic and relationships in the fanfic.
The Marauders reading the 'Goblet of Fire' fanfiction would be an interesting scenario. They would likely have strong opinions about how the original story elements are adapted or expanded upon in the fanfiction. For example, they might be intrigued by how the fanfic writer has developed the character of Cedric Diggory, who plays an important role in 'The Goblet of Fire'. They may also compare the fanfic's version of the Dark Lord's return with what they know or suspect from their own time. And they could have a good laugh or be seriously annoyed by how the fanfic portrays some of the Hogwarts professors.
Sirius, being adventurous and bold, would probably enjoy the more action - packed and dangerous parts of the fanfiction. He might be looking for the same kind of thrills he had in his own Hogwarts days.
They might be quite shocked at first. Since Wolfstar is a ship about Sirius and Remus, it's a modern interpretation of their relationship. The Marauders might not understand some of the modern concepts and language used in the fanfiction.
If the marauders read the epilogue fanfiction, they would probably have mixed feelings. On one hand, they would be curious to know what happened to the next generation. On the other hand, they might be a bit disappointed if the fanfiction didn't align with their own ideas of how things should have been. Maybe they would start to think about how different their era was from the one described in the epilogue.
They might be really surprised. They could find some new interpretations of the story that they never thought of before. Maybe they'd be amused by how fans see their characters in the fanfiction.
In Goblet of Fire fanfiction, there are often many characters from the original series. You can expect to see Harry Potter, of course. He is central to the story. Hermione Granger and Ron Weasley also play important roles. Then there are characters like Cedric Diggory, who is a key figure in the Triwizard Tournament. And villains like Voldemort and his Death Eaters also make appearances, which adds to the tension and drama in the fanfiction.
They might find it really interesting. They could compare the fanfiction versions of events in 'The Sorcerer's Stone' to what actually happened in their own Hogwarts days. It would be like looking at their world from a different, creative perspective.
Well, Sirius might find it quite amusing. He'd probably chuckle at some of the creative interpretations of the wizarding world from a female perspective. James might be a bit more critical, comparing it to his own experiences at Hogwarts. And Remus would likely be the most open - minded, finding value in the different takes on the story that the fanfiction presents.
Well, they might be really surprised. They could find some interesting interpretations of their own characters. For example, they might see how modern fans view their friendship and their adventures in a whole new light. Maybe they'd be amused by the creative liberties taken in the fanfiction.
One interesting plot in this kind of fanfiction could be that the Goblet of Fire is actually under some dark magic influence. Harry, being summoned, discovers this conspiracy. He then has to not only deal with the Triwizard Tournament tasks but also find a way to break the dark magic's hold on the Goblet. This could involve him delving deeper into ancient magic lore and seeking help from the Forbidden Forest's creatures that are often overlooked in the original story.
One possibility is that Hermione could use her intelligence to help Harry figure out the mysteries of the Triwizard Tournament earlier. For example, she might quickly decipher the clues related to the tasks. Maybe she could also prevent some of the dangerous situations Harry gets into. In the fanfiction, she could be more involved in Harry's training for the tasks, sharing her vast knowledge of magic to give him an edge.