This looks really cool! The more you look at it, the more details you see! I love how the knight and the horse are not what they are at first glance- they're one robot! And the dragon creature being the only living creature, you feel sorry for it having such an opponent to deal with.
I'm fond of the fluent pose of the whole design, too! The way the knight's helmet looks, that fluffy part of it bending in the wind. I like the beak-like design of the helmet itself too. And the face of the horse. It looks creepy like robot-ized animals often are, giving you the strange illusion of life.