Although it was just a brief exchange of blows, Ning Cheng could tell that Lu Yixian's strength was far superior to the others. He suspected that even when Lu Yixian had made a move against Artian, he hadn't used his full strength. Lu Yixian was strong, but when he said that bringing out the Unicorn Copper Lamp would allow him to kill Ning Cheng, Ning Cheng simply didn't take it to heart.
Lu Yixian had his trump cards, but did he think Ning Cheng had none? If it weren't for the presence of others, Ning Cheng would have already brought out his First Naihe Bridge. He didn't believe that Lu Yixian could cross over his First Naihe Bridge.
If the two of them were to fight to the death, Ning Cheng believed that he had a ninety percent chance of killing Lu Yixian.