Thanks to the lovely folks at CA.org I've tightened up my thumbnails, eliminated one and added one more. Which do you like now?
I like them all. In the top left one, think carefully about the inertia of the dragon flying alongside the riders and attacking the horse. Is he going faster? Is he going to knock the horse over or pick it up, pulling it forward as it swoops away? What's the angle of his attack? Is he coming in from above? Really catch the feeling of air through his wings, of catching that air, and see what you can blur to emphasize the speed.In the top right one, that dark horse on the left is out of perspective. Even if he's veering off to the right, his hind legs should still be more facing us. Try to find images of horses jumping, where they're running toward the viewer.
personally, I liked the Dragon's perspective of the previous C.