oh god, love your colors! Just amazing...! I think there might be some anatomy issues though. The hand holding the sword seems to be too small (should be able to open to be as big as the face) and there seems to be something off with the eyes.
This has great energy in the way you set up the colours for foreground and background. You've also framed her nicely. She definitely stands out, but at the same time is integrated in the scene. I also have to compliment on the armor design - as someone else already said, it's by far better and more practical, than the average show-as-much-skin-as-possible armor. Probably the stomach area needs more thought, because right now it seems immobile to me, at least if she were to bend forward. I might be mistaken, but it looks like you should find a three-quarter view face reference. Her eyes look off to me, and probably defining her right cheek bone might help, too. I belief her right hand should be a bit bigger, compared to her head.
Beautiful on every level, I love this artwork! Your design, pose, and even the sword itself is very creative! This is something I would expect to see hanging on the walls of some fantasy Hall of Justice!
As far as fantasy armour for females goes, this is pretty awesome! I mean, not totally practical, but still, MUCH better than what you usually see in terms of practicality and not sexualizing. And for that, I must say, thank you! Also, I enjoy your style, it's really cool!