Fallen angels can reveal things to humanity too.  The serpent tempted Eve in Eden which sat upon a height (The Life of Jesus Christ and Biblical Revelations, Volume One, 3. Adam and Eve Driven from Paradise, Anne Catherine Emmerich).  God gave Moses the Ten Commandments on Mount Sinai.  Jesus taught the Beatitudes on a mountain.  The two hundred, the fallen progenitors of the Nephilim, misled and abused women on Mount Hermon.  These spirits possessed and dominated them while also passing on occult knowledge.  The women and their offspring gained powers through this union, including those sometimes witnessed during exorcisms.  The women even invented music (The Life of Jesus Christ and Biblical Revelations, Volume One, 5. The Giants, Anne Catherine Emmerich).  Their children would become unnaturally large, a progeny of giants.