Artist's description:

"Hello!! I just wanted to make the mane 6 + sunset as princesses,and ended up creating an Au about it qvq i'm WeAk Btw this is a base edit!! It was so much fun!! I was kind of afraid that some of you would get mad at me for using bases qvq idk I don't have all the ships for this one qvq just Sunsetx Twi and PinkiexSkystar, so feel free to suggest one!!

Basically in this AU to defeat Tirek, Cozy and Chrysalis Celestia and Luna give up all of their magic and their physical form to make all the mane 6 ascend to alicorns. With the two sisters gone Twilight gets the role of Luna while Sunset gets the role of Celestia.

Twilight: Queen of Equestria, ruler of the night and element of magic.
Sunset: Co-Queen of Equestria, ruler of the day and "element" of empathy.
Applejack: Princess of abundance, element of honesty.
Fluttershy: Princess of nature , element of kindness.
Rarity: Princess of inspiration, element of generosity.
Pinkie: Princess of happiness (party queen), element of laughter.
Rainbow: Princess of storms, element of loyalty.

The bases i used are by polymercorgi ElementBases TeePew and Nocturnal-Moonlight"