Hey, I was thinking if an evil version of the Mane 6 we're too appear I'd like to think that while they're be opposites of the girls they'd also have a villainous friendship with each other, making them as close as the Mane 6 themselves, now THOSE would be some good opponents. They're friendship's with each other would also kind of be like the Red Lotus group's (from Avatar: The Legend of Korra) friendship, at least that's how I would do it.
What do you all of you think?

I like it