the way "the king's affection" applies to hyun like he rise to the throne not only because there is no other suitor left but more like he's willingly glad to carry's hwi burden as king, so he can powerful enough to make decision so she can finally be free to live her own live, and to finally see her happily live with her loved one, aka also his best friend. his affection for her make him take the throne he never want to begin with, he stand alone without any single family left because they're all died and he has no choice but let them be in order to protect her, and his people he treasure dearly live far away from the palace.
that scene when hyun sit alone on the hills, enjoy the scenery and the sweets he used to share with hwi, really heartbreaking. he looks so lonely, yet he faintly smiled, because he knows he made the right decision and he will do the same thing again if he's given second chance. his affection for hwi is just so pure and unconditional.
