What are the allusions to the idiom loose orpiment?

Wang Yan, a talkative man in Jin Dynasty, liked to talk about books when he was young. Once I went to the home of Dan Tao, a famous person at that time. After he left, Dan Tao looked at his back and sighed: "Alas, there is no such smart person in the world as I want, but I am afraid that it is this person who will miss people all over the world in the future." Lu Qin, the prime minister, heard about Wang Yan's "theory of union" and recommended him as the prefect of Liaodong. Unexpectedly, Wang Yan didn't keep the appointment, and Lu Qin realized that he was just an armchair strategist. When Wang Yan later became an official, he rarely did office work and often asked people to chat endlessly. He likes to brush off the deer's tail and talk about Laozi and Hyunri in Zhuangzi, but in the discussion, he often tells the wrong truth about Laozi and Zhuangzi, which is full of loopholes. If anyone questions Rebecca, he can change it at will. People say that he is "orpiment in the mouth". A few years later, the Valerians revolted in Shile, and Wang Yan was captured. In order to survive, he suggested that Schleswig be proclaimed emperor. Schleswig hated this kind of infidelity, thinking that a traitor like him caused chaos in the world and brought untold suffering. In a rage, he took Rebecca away. ..