Shiina Phantom-Vampirism

The sky is pretty. I like the swirling designs in it and the purple sun rising over the pyramids. It gives the picture a good reason for everything in it having a purple tinge. I also like that you used different shades of purple, darker for the sky, warmer for the hair, and a light lavender for the floating weapons. The different colors used on the victim make him stand out, both for the colors and the fact that he's the closest to the audience, but it's not too different that he doesn't fit. The pose on the woman is pretty good, and the perspective on her legs work pretty well. 
Criticisms:
1.Her hands seem much bigger in proportion to the rest of her body. Hands and feet should be about the same length as a character's head. The hand holding her knife seems especially weird, with her thumb being so low on her hand. 

2.The ghostly weapons are a cool concept, and I think you've got the right idea with the shade of purple you used, I just personally think they should either be glowing or be completely see through, since right now they look kind of flat. 

3. The outlines are very sketchy, messy, and flat. There's a way to make sketchy lines work, but usually not on a colored piece. The lines all have the same consistency, they're all very thin. Try adding some thicker lines on parts of the drawing that you want emphasized.  A really good opportunity would be to give thicker lines on the front of her boot, since it's very much in the foreground and the first thing the audience is going to look at. Same on the arm of the victim. 

4. It took me a while to figure out what was going on in this picture since there's a lot of similar colors close together. Specifically the pyramids, her coat, and her boots are all the same color, which makes it hard to make out what's going on. Since this character is meant to be menacing, I would go with a darker jacket, either black or dark purple, same with her boots. The little tendril of her coat that's going around her boot was confusing. 

5. The throne she's sitting on is also confusing. It's not really well defined and it's just sort of this grey mass. When drawing with dark colors, particularly black, what you want to do is fill it in with a dark colors,  (I use royal blue), and then outline in either white or some really light shade of whatever color you'd like, and then fill in the black on another layer. 

6. The skull is oddly drawn. 

7. What's that purple thing next to the skull? It's the same color as all the blades, but I can't tell if it's meant to be a bag or a floating axe blade. 

8. I'd go with a dark fur color on her ears. Since she's meant to be menacing/goth, a black or dark gray fur would work better to convey that. Or maybe try some designs without the ears.