How Demons Appear in Dreams
Refuah
Rav Yehuda Fatiya brings examples of how demons appear in dreams in the form of tzaddikim or as “ascended masters.” They can show dreamers images of the heavens, the holy throne, or even Kabbalistic symbolism, all in an attempt to convince the dreamer to believe what they send him. In this way the forces of evil ensnare another soul. The demons always begin by showing images of holiness, to convince the person that what he sees in his dreams is kosher. Once the soul is convinced and believes what it is shown, they lead him step by step until the person sinks into mental illness, and in that state they can control his mind and body. The only way to avoid the onset of such an attack is to recite the full order of the nighttime Shema Yisrael prayers. The Zohar teaches, “When a man's soul ascends above as he sleeps, if he is sinful then his soul is cast about from place to place by the forces of the powers of evil. This is why one sees himself in a dream in another country or in another land.”
Source: Minchas Yehuda; Zohar III, 222b