there's so much to explain. What exactly aren't you understanding? I'll try to explain the gang drama. There are several Asian gangs. They ended up forming a coalition called the Golden Bird. They came to an agreement to work together instead of fighting and killing each other. TJ was a major player in forming this coalition. For some reason (that hasn't been explained yet)the head boss of K35 (Big Boss/Jason's brother) wanted to kill TJ. So they tried to kill him in season 1 by using Jaime to go after TJ. Jaime staged that car accident. After Jason's death, TJ is meant to take over his position. So that would make him 2nd in command now under Big Boss. He snuck in to visit Big Boss to strike a deal with him to back him up during the executive meeting , agreeing to stay a loyal dog to Big Boss. But he already made plans in case he gets betrayed by Big Boss. When TJ came to the executive meeting for his promotion to Jason's position, Big Boss tried to kill him again (car bomb) So now he has to take out Big Boss and Hwan and whoever is on Big Boss' team because they keep trying to kill him. So TJ went to the other gangs in the coalition to let them know his plans on taking out Big Boss and the other members of k35 on his side during the wedding since everyone will be there. The members of the coalition was on board with TJ's plan because they didn't let a big boss know and all started leaving one by one allowing TJ to come in and kill everyone.