大乘起信論裂網疏 6.63

6.63

Here, it first distinguishes the forms manifested by demons. If the practitioner's habit of fear is heavy, they mostly manifest hideous shapes to terrify them. If the practitioner's habit of craving and affection is heavy, they mostly show beautiful forms to bewitch them. If the practitioner's power of wisdom is weak, they mostly manifest forms of devas, bodhisattvas, and Buddhas to deceive them. In all cases, it is the so-called 'if the host is confused, the guest takes advantage of it.'