This is so dramatic and wonderfully done, I hardly know where to start. Your use of perspective is really top-notch! The colors you chose for this palette are really eye-catching and work very well, I love the way it gradients from warm to cool in the background, giving a sense of depth to the building in which she's standing. The feeling of movement is greatly enhanced by the floating pieces of paper.
To me, the thumb in the foreground looks slightly off compared to her fingers, as if the hand is a little too long between where the thumb joins and the first knuckle of that index finger. I also think the right upper arm could use a little more definition, the shadow across it makes it look skinnier than it should be at first glance.
Intense and lovely piece, you should be very proud!
In my opinion, your perspective is great. It leads well to a feeling of movement. Looking upwards, almost wide angle, and the character in this pose, gives a sense of movement.
The vertical pillars are awesome - it ads to that wide angle feeling. The character pose is spot on. Very nice.
The character itself is well done. She has a good natural look. The clothing looks real. The armor is appealing. The detail on the armor is very nice. I love it. I'd love to a see a 100% crop of the arm band, to get a gander of all that detail. It looks impressive.
The floating documents with motion blur, also ads to the sense of depth, as well as movement. Good props to add to the scene.
What I actually like very much is the speckles in the air, near her coat tail (bottom right) - I like it. It looks like something that flew off her coat (dust/water droplets) and got lit in the sunlight.
The tones are good.
The only thing, and this could be my personal taste here, is that I feel the colors blend so much from the character to the background that there isn't a lot of separation. Maybe a stronger contrast in color might be nice. Or maybe that would not work. It's hard to be certain just thinking about it. I dont think you could push the color of the coat much more then it is. But maybe the skin tones could be bumped a bit. I really can't be sure i'm even right about the tone, I'm just thinking out loud.
Overall - awesome work. I like the hair. I struggle with hair. In fact i have a piece on deviant art and I'm struggling with the beard. You did a great job with her hair.