honestly agreed but i think kai is morelike a sociopath than psychopath tho. sato is one pure psychopath motherfucker.
yes you are right in that, i mixed the terms of the two disorders , the difference between them is that Kei still have a tiny little conscience ... lol and he dont want to kill others only have a peaceful life and a place in society. to be more correct Kei is a Sociopath but i still see some psychopath traits in Kei in a slight way , even so i think he(Kei) is not a violent psychopath ( there exist diferent levels in this disorders ); at lest not like Sato that is the tipical sociopath-psychopath as you say , he is one pure psychopath motherfucker
I will give my opinion so please don't crucify me (=・ω・=)
Sato and Nagai Kei personalities were created in a almost perfect way , the psychopath teenager Nagai kei (a Ajin ) vrs a sociopath-psychopath Sato and (Ajin too giggles ), the mangaka, he put so much into the two character that made this manga so great,even in the way they think and act , i really love it . Even how the so called "human" (smile ) react and behave, his understanding of human nature is amazing. He really have to put a lot of reserch to do this manga. He made me wants to see more ヾ(☆▽☆)