Well, in some fanfictions, Draco might realize the error of his ways. Maybe he starts to see the Golden Trio's true qualities, like Harry's courage, Hermione's intelligence and Ron's loyalty. This new understanding could lead to the start of a friendship.
Perhaps a plot twist where Draco sacrifices himself for the Golden Trio. In a moment of danger, instead of saving himself as one might expect from his Slytherin self - preservation instincts, he chooses to protect his new friends. This would be a huge shock and a great development in the story of their friendship. It could also lead to the Trio then finding a way to bring Draco back to life, which would be another interesting turn in the plot.
It changes it a great deal. Firstly, the group dynamic becomes more complex. The Golden Trio was initially based on friendship and a common goal against Voldemort. With Draco in it, there could be more internal conflict at first as his background and beliefs are different. However, over time, it could add a new layer of depth. His family connections might provide different resources or insights that the original trio didn't have. And it can lead to some really unique storylines where they all have to learn to trust each other despite their differences.
Well, a frequently used plot device is the clash of values. Draco has been brought up with Slytherin values, and the Golden Trio has their own set of Gryffindor - like values. This clash can create a lot of tension and drama in the story. Also, there's the idea of Draco being an insider - outsider. He has ties to the darker elements in the wizarding world through his family, but he's now part of the 'good guys'. So, his knowledge of the other side can be used to help the trio thwart evil plans. And of course, there's the inevitable love triangle or relationship drama that often pops up, whether it's Draco having feelings for Hermione or vice versa.
The founders might be quite surprised by the Golden Trio. They could be impressed with their skills and knowledge. For instance, Hermione's vast magical knowledge would surely catch their attention.
They'd probably start off being really cautious around each other. The Golden Trio would be cautious because the Winchesters seem so different and rough. The Winchesters would be cautious as they're not used to this kind of magic. But then Hermione might start asking questions about the Winchesters' hunting methods and Dean would start joking about the Trio's school - like magic.
They might be really surprised. Harry could find it strange to see different versions of his own story. Hermione would probably be critical at first, analyzing the plot holes or inaccuracies compared to the real events. Ron, on the other hand, might find some of the more comical fanfictions quite hilarious.
There are often fanfictions that explore different relationships within the golden trio. Maybe a story where Hermione and Ron have a bit of a falling out, and Harry has to play mediator. It delves into their complex friendship dynamics and how they grow from such experiences.
One interesting Dark Golden Trio fanfiction could be where they go on a secret mission outside of Hogwarts. It might involve them using their combined skills in a unique way to solve a mystery that the adults in the wizarding world have overlooked.
Well, it could be a total chaos. The Golden Trio from Harry Potter are used to magic in a very different way than the Winchesters deal with the supernatural. Maybe they'd start comparing their magical tools. Harry could show off his wand while Sam and Dean might be intrigued by it, or they could teach the Trio a thing or two about hunting demons.