Following on from - and maybe helping Blue-SilverDragons point, the castle has too many towers, turrets and spires for it's architectural footprint, Perhaps add more effects and personality to the castle to distance it from the Mortal architecture it is based upon.
I like the light through the cloud and sky, There could be more doodads about but in the time and scale that's good . I wanted to suggest lights in the castle to increase it's presence (by say removing turrets) but actually I like the ambiguity of it being unlit...