This is actually NOT a genderswap of Elsword, its his Sister Elesis, which is a new character(in Elsword, at least) that's going to be released soon on the Korean Elsword Servers. Note that the image is even Titled Elesis on its pixiv page.
And yes, she is also in Grand Chase, and has been in it for a long time.
Those it mention that this Elesis is the same in GC too?
This is confirm to be Elesis but due to the two games, Elsword and Grandchase, being in 2 different companies they kinda have to scrap the idea that the two are related to avoid copyright problems. Well, at least in the North American and probably European Servers. I'm not sure about the other countries.