Demons and Apocalypse
Two videos I recommend to anyone interesting in the topics are these:
The first is an interview by Michael Knowles of Rev. Daniel Reehil, one of the most calm, level-headed and sober figures I have ever seen, an exorcist. Several things said by the father caused me to pause and ponder my own life, as well as my own prayer life.
The second is a lecture series on interpreting the Book of Revelations.
https://www.youtube.com/playlist?list=PLnftOVqh-jlZIKgatk6uEi4l7hdXTmTHM
More useless ink has been spilled over this topic than any other, and I am frankly contemptuous of the approach of most popular interpreters. This lecture alone proceeds in what seems to me to be the sole rational approach, that is, to interpret the images in the writing of Saint John in light of the way earlier images were used in Daniel, or Ezekiel, or another prophet.