Qingfeng didn't stop Zhengtian Gu and Jianghe Tang from leaving, because Zhengtian held great power. Even if Qingfeng were to kill him it would be at a great cost, something Qingfeng didn't find necessary at the moment.
Qingfeng had the "Alchemy Arts of the Elixir King" in his possession, and he knew that as long as he became accomplished in alchemy, and established relevant connections, say in the Dragon Palace, then it would shock the four big martial families of Tianjin city. Then he wouldn't need to do any of the dirty work himself.
"Thank you for your help Miss Qin, this is the life-prolonging pill. It can prolong your father's life for another month." Qingfeng smiled and handed a silver-white elixir to Xianzhi.
It really was the life-prolonging pill, Xianzhi looked at the elixir in her hand that glowed with life itself, her attractive face overwhelmed with gratefulness.