Your complex lighting looks good and so do the boxes, the only thing I noticed was that the shadow for the green box is a bit off. The light is coming from above the front left corner so there shouldn't be a shadow in the front.
With your character design, I think you're off to a good start, but I think a few more thumbnails wouldn't be a bad idea. You've got some good ideas down but all I'm getting from the thumbnails you have is a knight. Try to tie all the elements together and give them a bit of a backstory. Don't make a novel or anything but something along the lines of " After failing to save their lord this knight has wandered the land for ten years seeking revenge." So with this, you could say that the armor is a bit beat up and a few pieces are missing or mismatched. Give him a beard to show that he's been away from any kind of high society.
hope that's helpful, keep up the awesome work