If you are referring to how he doesn't feel pain, I don't think it is that he is a sociopath. I read a case where this woman didn't feel pain at all and it was due to a medical condition, and it is not so rare, there are many people like that. I think it is like your brain blocks off all pain receptors so you can feel a touch, a hug, and so on but no pain, I might be wrong tho
No. He isn't, but you know when our mom teach us that nobody own us nothing , and if we wants something and someone don't want give that, that is ok, because nobody own us nothing. So the emperor wasn't, everything and everyone he wants he gets because he is the emperor, but gok don't give a shit. So if read the two last chapters when gok see that the lil prince want the birds, and gok have to explain why he shouldn't put birds in cage, in that moment gok realized that they mentality (emperor and prince) is what i want i get, and when they try to runway put than in cages, or broke thay legs, foot or wings.. for than don’t try again. Because what I want is mine... they are surrounded by YES SIR! And they don't know how to deal with the no. And the thing about thepain is that they never got hurt, and they always have someone giving their life to protect the emperor..and he is feeling for the fisrt time what is pain... mentality and physically.
Mentality because he don't know how to deal with gok rejection. When he says that he heart is getting cold that would broke in pieces.
Physically by the cut in the hand, because he even say that he could've die from that cut losing blood... lol
CONCLUSION:
HE IS A KID, IN ADULTS BODY!!!

So the emperor is a sociopath?? Or very similar to it at least?