Everyone is smart. After listening to Cheng Sheng's words, they finally realized what's wrong with Ma Wen's people. 

"They disguised themselves?!" they exclaimed. 

"I guess." Cheng Sheng spoke. 

Xiao San pondered. "But, you've let us borrow the Mirror of Truth…" he said and looked at the mirror in Wu Yuan's hands. 

"This is where the real problem lies." Cheng Sheng muttered as he turned to him. "I am guessing that someone was using a large-scale spell to interfere with our senses." He explained. Fei Yin told him everything earlier when he woke up. 

They were stunned. "So, that's why even though I can recognize the citizens of the Drunken Moon City, but still can't find Ma Wen's people." xiao San muttered as he clenched his fists. 

Meng Gui patted his shoulder to console him. Then, he turned to Cheng Sheng. "The food will be eaten by everyone in the Drunken Moon City. Will this have any effect on our own citizens?" he asked. 

Cheng Sheng shook his head. "No." he answered before he paused. "If there really is, then it will just cleanse their meridians." He said. 

The Origin Bone is the crux of the Form Revealing powder. The Origin Bone isn't a bone, but a stalk of the Five Black Petals Flower. The stalk of the Five Black Petals Flower gathers the qi from the dew that the petals absorb. So, it is of a pure essence. When a magic pill or potion containing the Origin Bone, it cleanses one's meridians. So, if one changed themselves to disguise, then the Form Revealing powder will remove the impurities in their meridians, making them exposed themselves. 

"You should also drink a Spirit to make your senses sharper in case the spell would stun you again, making you miss the time when Ma Wen's people would change after they ate the food sprinkled with Form Revealing Powder." Cheng Sheng sincerely told them. 

"'Spirit'?" they asked. 

"This won't be harmful to us, right?" Shang He asked. 

"I won't harm you." Cheng Sheng spoke. 

They all fell silent. They have to admit, although Cheng Sheng's tongue is sharp, but the righteous cultivators have been helping them. 

Seeing their expressions calm, Cheng Sheng spoke. "Spirit is a potion to reinvigorate one's nerves, thus sharpening your senses." He explained. "It's not harmful to you. Spirit can be drunk by both the righteous and demonic cultivators." He told them. 

They all sighed in relief. "So, where is it?" they asked. "Why didn't I hear of it?" they added. 

"I brewed it myself." Cheng Sheng answered. 

Everyone looked at him. The wind blew past them, making their robes flutter. Their gazes fell on Cheng Sheng's waist that was exposed after his robe fluttered. They saw a sheepskin leather belt wrapped on his waist with five badges imbued with colorful gems hanging on his belt. 

"Mage's belt. Master level." Wu Yuan briefly explained. 

The demonic cultivators. "…" what's with this sudden feeling of insecurity? Although they are demonic cultivators, but they admire mages since mages can both fight and also make their own magic pills and potions to make themselves more powerful. And, Wu Yuan is saying Cheng Sheng, this scholarly-looking cultivator is a master level mage?! 

They looked at Cheng Sheng. Their eyes that were full of hostility and killing intent earlier now are filled with admiration. They didn't know that Cheng Sheng is a mage. After they did, they thought that Cheng Sheng is just an ordinary mage. But, it turns out that he is actually a master. 

Although Wu Yuan looks indifferent, but there is a faint smile in his eyes. Fei Yin, on the other hand, is grinning, filled with pride. 

"He has four apprentices." Fei Yin spoke. "Two are talisman mages, where one is our shidi. One is very intelligent and is his shixiong, learning spell casting and arrays from him. The last one is our shimei – a potion mage." He explained. 

The demonic cultivators. "…" do you have to brag?! They thought, then sighed in defeat. Although they wanted to learn from Cheng Sheng, but they are demonic cultivators who specializes in poisons. Cheng Sheng is a righteous cultivator, and specializes in potions. Although he said 'poisoning' earlier, but the 'poison' is just a powder. 

Cheng Sheng saw them brooding. "Actually, everything has its own use." He spoke. 

"Huh?" they looked at him. 

"Your poisons can be used by righteous cultivators." Cheng Sheng said. "… who has ill intentions." He muttered. Although he said it in a low voice, but everyone still heard it. 

The demonic cultivators. "…" although they wanted to get angry, but they can't prove Cheng Sheng wrong. So, they are stifled with anger. 

"But, potions and magic pills can also be used by the demonic cultivators." Cheng Sheng continued. 

They stared at him. 

"Potions and magic pills can even be used by ordinary humans as medicines. Although there are some potions and magic that is restricted to you because they contain some ingredients that is harmful to you, but the remaining others are still usable, right?" Cheng Sheng asked. 

Everyone immediately felt enlightened. Because they thought that they are demonic cultivators, they should only use something related to demonic cultivation and can't with anything related to righteous cultivation. They aren't stupid to not try this theory. But, this theory turned to a conjecture after they saw someone fell ill and die when that demonic cultivator took a potion to increase his strength. There is a proof, so they believed this to be true. 

But, after hearing what Cheng Sheng said, they felt that the clouds in their mind disappeared. 

"So, it's because of the ingredients used in the potion that that demonic cultivator died?" xiao San asked Cheng Sheng after they told Cheng Sheng of what happened before. 

Cheng Sheng nodded. "There also must be other factors that played, like his weak constitution." He said. 

They looked at each other. 

"I can only prove it to you tomorrow." Cheng Sheng spoke seeing the doubts on their faces. 

They turned to him. 

"The citizens of the Drunken Moon City are half-demonic cultivators." Cheng Sheng looked at them. "After they eat the food with Form Revealing Powder tomorrow, you check whether they will fall ill or not." He said. 

Meng Gui and Shang He, although more careful than their subordinates, but they can judge people who wants to harm them or help them. Cheng Sheng, Fei Yin and Wu Yuan definitely belong to the latter. 

"When will you concoct the Form Revealing Powder?" Meng Gui asked. "What do we need to prepare?" he added. The Drunken Moon City is his territory and everyone living in it are his people. So, he is the one responsible to provide what is needed to help them… protect them. 

However, Cheng Sheng just stared at him. 

"What?" Meng Gui asked, suddenly feeling conscious by Cheng Sheng's stare. 

"Leader Meng… is actually a good person, right?" Cheng Sheng asked. 

Meng Gui's eyes widened and he blushed. "I – I'm not…" he stammered. 

"He is." Shang He spoke. Their subordinates nodded. 

Cheng Sheng looked at them before he spoke. "No need." He said. 

"Huh?" 

"I have the some prepared. But, since a large amount is needed, I have to concoct the rest." Cheng Sheng spoke. "I have the ingredients. I only need a room where I can refine the ingredients without any disturbance." He told them. 

Meng Gui nodded. Then, he turned to xiao San. Xiao San understood. "I'll prepare it!" he said before he left with the other subordinates of Meng Gui. 

"Is there anything else you need?" Meng Gui asked as he turned to Cheng Sheng. 

"Yes." Cheng Sheng nodded. Before they could speak, he continued. "But, since this is the Heilong Realm, then you won't find it, like the ingredients for Form Revealing Powder." He said. 

Fei Yin who understands his lover very well. "…" oops. 

Wu Yuan who is familiar with Cheng Sheng's scum personality. "…" ah. He thought, his face indifferent. 

It took the demonic cultivators a long time to understand what he meant. And when they did, they almost erupted. "…" so, he thinks that everything here is impure?! They thought as their faces darkened. But, since he is helping us, we have to endure! 

"Right – " Shang He coughed to relieve the awkward atmosphere. "How do you know that there is a spell covering the Drunken Moon City?" he asked Cheng Sheng. 

Hearing the question, everyone immediately looked at Cheng Sheng. 

"I am more sensitive to the qi of the nature than the others." Cheng Sheng answered. 

"Why? How?" the demonic cultivators curiously asked. Today, they find Cheng Sheng filled with mystery. 

"It's because of his cultivation method." Fei Yin answered for Cheng Sheng. 

The demonic cultivators naturally know there are many cultivation methods. 

"What is the cultivation method he is practicing?" they asked as their gazes all fell on Cheng Sheng. 

This time, it was the silent Wu Yuan who answered. "The Art of Purity". He said. 

The demonic cultivators. "…" they thought it was only Cheng Sheng. But, who would know that even this cold-looking Wu Yuan is actually also disagreeable! They are all mocking us right?!