Zhao Changhe had long known of this technique.
Originally considering Kong Shi, who is Bodhisattva, as his imagined enemy... What is Bodhisattva? Buddhism's designated Heavenly Demon, enticing the hidden evils within human hearts. It would be strange if He didn't play mind techniques.
Back when Yue Hongling was traveling alone in Kunlun, she had already fallen for His tricks more than once, and of more than one kind. She first fell for an incredibly real Mirror of Inquiry, attempting to absorb her soul, but after Yue Hongling broke free, her inner thoughts were also read, resulting in her seeing illusions of fake products many times in the Kunlun Secret Realm, which she then broke through one by one.