This is a very interesting concept that I never would think to do on purpose, due to their malevolent nature and energy sucking tendencies.
I have never done this, therefore, but I do have a couple situations with them. It sounds like an interesting book to read, though.
They seem to know when an individual is in a weak or vulnerable state and manifest then, around illness, stress, intoxication, or general 'bad vibes.'
When I was starting out my journey with ritual magick, I would often be drunk too often, and I would not close ritual circles properly.
I would see them 'dancing ' 'circling' on the walls in my ritual space. Sometimes I would get a sense of 'happy evil glee' at sucking up my weakened state.
I don't think this was hallucination, I was not blackout inebriated and trying to do any rituals, I was just buzzed, but in a negative place mentally, from too many depressants and a job I hated, working the graveyard shift.
Many traditions suggest that shadow people (or parasitic astral intelligences) are generally encountered by descending vibrationally into states of exhaustion, intoxication, depression, fear, obsession, or psychic instability — a lot of what you described. In a sense, one lowers their own energetic frequency enough to become perceptible or compatible with theirs, intentionally, or non-intentionally.
That is why they so often appear around liminal states — sleep deprivation, illness, addiction, grief, trauma, heavy ritual work without grounding, or prolonged negativity. The magickian becomes psychically open, but without proper protection or centred intention, it creates resonance.
Your description of them seeming almost gleeful or feeding from weakened emotional states is very common in reports surrounding these entities. Many esoteric systems describe certain non-physical beings as feeding upon psychic discharge — fear, despair, anxiety, intoxication, sexual obsession, rage, etc. Not unlike how some traditions describe larvae, astral parasites, or qliphothic intelligences.
That said, some occultists intentionally work with these currents, though it is generally considered dangerous for precisely the reasons you mention. Invocation or contact often involves entering altered states that partially mirror the entity’s own frequency. In practical terms, this can mean ritual darkness, trance, sensory deprivation, exhaustion, intense emotional states, intoxicants, or deliberately entering the shadow aspects of the psyche. The danger is that prolonged exposure can begin to erode psychological balance, vitality, or personal sovereignty if one lacks discipline.
As for knowledge gained from such entities, traditions throughout history suggest that intelligences dwelling in 'lower' or shadow strata may still possess insight — particularly regarding hidden desires, trauma, taboo knowledge, manipulation, the unconscious mind, death currents, primal instincts, or aspects of the self one normally represses. In some systems, confronting or working with them is viewed less as “learning from demons” and more as descending into the underworld of the psyche to recover hidden knowledge.
The problem is that the information often comes at a cost. These entities are rarely described as benevolent teachers. The knowledge may be distorted through fear, ego inflation, obsession, dependency, or psychic attachment. Many occult traditions therefore stress discernment, banishing, grounding, and maintaining sovereignty over one’s own will before attempting any form of contact.
Honestly, your experience sounds less like simple hallucination and more like a classic example of ritual vulnerability — intoxication, emotional depletion, graveyard shifts disrupting circadian rhythm, and unclosed ritual work creating the perfect conditions for those perceptions or encounters to manifest.
