This is fantastic! I love the details and coloring. That background is something too.
Some creative criticism, his right leg (your your left) looks a bit odd, like his knee got kicked in. The way yo have the top of his leg makes it look as life thats the direction his foot should follow but once your pass the sword his foot is going another direction.
I know that when your leg in straighten, from certain angles, your leg will look slightly curved inwards but with this piece, its a bit much. Your art is fantastic so keep working on it.