It didn't make sense for Tang Shaoyang to be angry with the criminals. They had done something that maybe deserved to be killed, and yet he was still angry when he saw them killed—certainly not because they were his temporary subordinates. He did not harbor such feelings toward these criminals; however, this reminded him of something from the past.
This reminded him of the time he was being used only to get stabbed in the back. He recalled the memories of when his boss tried to kill him even though he had been fighting on the street for his life for the boss. It did not happen just once or twice, it happened three times until he joined the last group where he decided to remain at the lower bottom runk despite his contribution to the group.