Compare the language here with Daniel 10:5-21—spirit beings fighting and being cast down, even as humans fight. Only when humans fight, the loser is cast down in defeat and death. With the angelic beings, they are cast down in defeat, but there is no death.
How, then, is essence cast down? Arguments that posit spirit to be essentially insubstantial begin to become ridiculous. How does one cast down smoke, if we can think of essence in terms of smoke? Did Michael and his angels find big fans and blow the demon essence toward the earth? No, these verses give every indication that these spirit beings have substance. They are spirit, but they are substantial, tangible (that is, "capable of being perceived especially by the sense of touch"; synonyms are "palpable," "substantially real," "material").
Gabriel touched Daniel, and he was aware of feeling a hand touch him on the shoulder. Another time a hand touched him on the lips, and he was able to speak. The hand had substance.
John W. Ritenbaugh
Image and Likeness of God (Part Three)