Generally, Lau's an easygoing and carefree man who frequently smiles and indulges in smoking opium. He is, on numerous occasions, accompanied by several women. He refers to his personal assassin, Ran-Mao, as his sister, although they aren't related by blood. Lau has a peculiar tendency to say or act like he's aware and well-informed of something important only to later reveal that he's, in truth, clueless. This particular trait of his often annoys others; Sebastian believes that Lau just chimes in whenever "he thought it appropriate." Lau has a strong propensity toward violence, which he showed when he told Ciel that he would kill Agni if he were Harold West Jeb — much to Ciel's surprise, since he found that to be a bit excessive. While Ciel was willing to spare Harold and Mina, Lau was not as forgiving and had Ran-Mao terrorize the both of them. Also, in his zeal to help Sebastian with a magic trick — which involved sticking multiple swords in a chest that Sebastian was in — he did so without thinking of the consequences. He even immediately attacked from the top; Sebastian later admitted that Lau had actually managed to deal minor pain to him, a demon. Lau is an expert in the use of needles and knowledgeable in human anatomy, as demonstrated when he effortlessly put Harold's guards to sleep with his needles.In only a few years, Lau managed to climb the ranks in Qīng Bāng and became a top official, receiving the sobriquet "Rising Dragon of the British Concession" in the process. He was then put in charge of The Bund in Shanghai. Around 1887, Lau became pen friends with Ciel, who helped him with his reassignment to London.