Angelique

Commissioned by Drusilla Wu.
The character is her OC fan-art from Dragon Age game franchise. The character's name is Angelique, a Rogue Assassin from Antiva. She's on a mission to assassinate someone in a ball, thus the dress, the dagger and the poison ring (and probably a dozen other assassination gadgets under her skirts, i'm sure, lol ).
Face is loosely based on Eva Green.