Very nice work, really digging the blending done on all the renders and the scene looks very natural. Aside from the slightly blurry castle on the left, it honestly looks like a single castle, not one made from two different renders. The best detail here is, in my opinion, the attention to the lighting on Nero: the shadow he projects on the ground, and the sharp lighting on his boots, from the lighting source on the right.
The only things that could be improved are the castle on the left (thought that would most likely mean redoing the entire render), and maybe making the fog a bit heavier and more "flowing"; the left side of the wall looks like it was "dabbed" with a brush (the fog looks "round"). Other than that - solid composition, solid colors, solid blending. An all around eye-catching work. Keep it up! :)
