Humans are really magical creatures. When they become indifferent to a certain extent, they become invulnerable. You can give up everything, family love, friendship, but there is only one thing, like a clear stream slowly flowing into this body that is almost dry. You will become a flesh and blood you, but a flesh and blood you is not invincible. You have a weakness, something you care about, something you can threaten and exchange.
Cheng Wei gave up his position as the young gang leader for Mu Liang and killed his enemies for him. Zou Ziqian was also so ruthless that he let Mo Xiaobai go because he didn't want to be caught in his weakness. "You little idiot, you may not know that you love me yet, so you run away as fast as possible. Run far away until I can't even find you. Then you will be safe."