Basically she's like the regular Emilia, except she doesn't completely suck. She gets more wizard stances, including levitation.
The catch is, though, they aren't giving her out freely, basically a lottery system, a random person buying gold (well, lacquers) this weekend will get her.
Lottery systems and random grab bags are one of the ways a company can squeeze the most possible money out of a devoted fan base. Because people will go crazy trying to get a super-rare item. This is the basis for collectible card (and other) games.
I know K2 has to make money off this game, but cash grabs like this are pretty tacky
SEA Update: Stance Revision
19 hours ago