So i stumbled upon this video. it’s an actual costume in-game, it was promoted as an event to obtain this costume.
It’s promoted by girls generation for B&S to popularize for Blade & Soul China.
It comes with their own custom dance like how ‘Summer Groove’ had their own /groove emote.
It’s apparently a girl’s generation dance, that they danced themselves. Also the dresses are what they actually wore at the promotion. ITS SO CUTE. will we ever get these?