Let me start off by saying that I really like this. Iv'e always found the concept of darkness withing a person cool.
I like the drawing style a lot but wish there was more detail on the energy field around her hands. I wish it was bolder and hard a particle effect to it, It would have really made it pop then. The concept of her hair growing when she is angry is cool too, i feel the hair should be spread out a bit though, it lacks volume towards the end and looks kind of limp.
I really like the glowing symbols on her body, the glow effect came out really well. A slightly wider upper torso would go well with the rest of the body, especially since the hips are curvy, it would just complete the effect.
Great work though,