More of the Dancerverse can be read from these two pieces:

And you'll probably learn a lot more from reading through the whole gallery:

The only physical difference Sunset Shimmer in the Dancerverse has with herself in the canon is that she ties up the back of her mane, that's it, but by the time I decided that she already had the pretty clothes on. At most, she'd wear the hat on and off again, like Trixie does with her's. Ignore her poofy neck thing.Okay, so! I spent a heck of a lot of braining on Trixie's part of the Dancerverse but haven't really put much thought in Sunset. I'd say she's a wandering unicorn who scours Equestria for ancient magical artifacts to increase her power, in a vague quest to become the most powerful unicorn (Majesty has you beat there, Sunny, you're like second place now).Sunny Shim probably encounters Moondancer and company the one day she decides to stop by Ponyville, maybe showing off a little only to be upstaged by Moondancer. Heckprobably the one who lures the purple dragon into town to prove that she's the greater mage. She fails, Moondancer uses her protagonist powers, Sunset flees in shame, status quo ensues.By the time Sunset Shimmer comes back for round two she's wearing the Element of Magic, an ancient crown with ties to Celestia and Luna's Element of Harmony, which has taken on the appearance of her cutiemark. Since they have the pieces of the Crystal Heartof them, the Mane 6 probably opt to friendship laser Sunset once Moondancer learns another lesson in humility, probably outsmarting Sunset in a magic duel but the latter refuses to hold up her end of the bargain because she's still more powerful.I would guess that by then she'd be like the canon reformed Sunset and has cut down on the hunt for power? If she is then her relationship with Majesty should be friendly enough, unlike Trixie's.("A blue mane and coat, purple eyes, and a starry cutiemark? Moondancer you've replaced me!" -both mares)