You are right the two characters Young-gyu and Jogu are differently presented, as a warrior Young-gyu has that expression on his face strong and decision maker.

On other hand Jogu has soft features, gentle and kind.

it is a sad story of defeat, but war is war, there are loses on both side, but the memory about that war and warriors still in the heart of the nations and still lives in the the Boseoksa.