Uh…. Yeah lol
he was indirectly influenced from the people around him. his dad was violent, his friends were violent and he literally joins a career that REWARDS violence. all he knew was betrayal so thats what he learned from, it doesnt justify his actions at all but it shows us why he's like this. I know that kim dan also went through similar stuff but i feel like thats the point of their dynamic, to show that trauma isnt one singular flavor; someone can go through this and become a kind, caring person. someone also can go through the same thing and become a shitty person, no human being is the same.
finally someone who gets it
...and? How is this supposed to explain Jaekyung's shitty and unmannered attitude towards everyone :DDDD