Chapter 847: The Scum Is An Invader 

Xie Lan and Ling Yun looked at Ho Ting when they heard what they said. "You… how did you know…?" they asked, before they turned back to look at Cheng Sheng, only to see that Cheng Sheng was silent. This confirms that what Ho Ting said is true. 

That is, the truth about the 'poisoning', and how it works. 

"Founder." Cheng Sheng called Xie Lan. "The prescription I made makes one's body, including their spiritual veins, stronger so that their spiritual energy would flow smoother, and their cultivation would be better. Thus, it could delay the 'poisoning' of the foreign spiritual energy in their body." He explained. 

Ling Yun's eyes widened in surprise while Xie Lan's expression turned serious. 

Xie Lan heard what Ho Ting said just now. "That means…" he muttered as he stared at his disciple.