Book of Demons: An A-Z of the Diabolic

People always underestimate how powerful, potentially harmful a Devil, Demon, Entity, Elemental can be.
They are powerful and they can influence, harm you, possess you, influence your thoughts, dreams, desires, give you nightmares, cause sleep paralysis, bite/scratch, rape you while you sleep..
They have psychic abilities, they can read your mind and see into your soul, they know your deepest, darkest secrets including anything you secretly desire but wouls be too ashamed to ever admit it to anyone.
Such is the power of Devils, Demons, Entities.
I have encountered Demons & I know from experience that they are real, powerful and potentially harmful.
However Demons can also be helpful if you are repressed as a person in multiple ways, they can help with empowerment, feeling confident and helping you feel confident in expressing yourself in a sexual way if your shy, not confident in that way/sexually repressed.
There are advantages & disadvantages to working with Demons spiritually/magically if your a Witch, Occultist etc
I like that the author included people that are a known Occultists people like Cornelius Agrippa, John Dee, or Aliester Crowley.
They were known Occultists that practiced Black Magick, John Dee practiced Enochian Magick.
Enochian is the language of Angels & Demons, but people demonized it and thought that John Dee was a controversial person for practicing Enochian Magick.
There hasn't been any Demonology book I have read so far that mentions well-known Occultists, Witches/Warlocks that practice witchcraft and they work with demons spiritually & magically.
The author mentions Nuctemeron & steganographic demons a lot and I have no idea what either thing is or what it means.
Googling them didn't really clarify it any further so it is frustrating & confusing because I don't know what it is or what it means