Brilliant work, especially with the wings- rather than drawing every feather, you sketch them in and let us see them for ourselves. Brilliant.
Two minor problems that I can see:
(1) The cant/angle of her hip is somewhat more horizontal than I believe is the norm; and (2) While this one is more about taste and artistic desire, I think the piece would be improved by a background. Some abstract pattern, probably - done in violets, reds and black.
Dint know the game but I like the detailing you put into her abdomen and decay details in her arms though how bad is the decay? Wouldn't her bones be showing? Plus I like her expression and how her sings seem to be falling apart. Though my only critic is the hands the one that has the purple glow around it is nice though it's hard to tell were the thumb is coming from and her other hand seems to disappear all together into her dress.