The Scum Is Frank 

Dong Cheng and Dong Zheng were looking at them. They don't understand what are they talking about, so they remain silent and continue to eat. Meanwhile, Lei Qing froze. She understood what Fan Wen meant. Lei Ling might no longer be suitable to create the barrier. 

Lei Qing remembered that one time when Cheng Sheng tried to teach them alchemy. 

"The first and foremost thing to remember in alchemy is that one has to have knowledge, but also have the will." Cheng Sheng spoke. 

"Why?" Lei Qing asked. 

"Because it is useless to have the knowledge, but not have the will." Cheng Sheng answered. "And vice versa. It is useless to just have the will, but not have knowledge." He said as he looked at each of them. "The former means that even if you have the knowledge, whatever you made won't have the true essence since you don't have the will. That is, the heart." He told them. 

They all fell silent.