What is Black Magic:
Whether done by people or spiritual beings black magic is the conscious malicious interference for self-centered egoistic goals (lust, power, control, money, etc.) of persons or groups into the being of somebody else without the other person(s) knowledge or approval.
To achieve this black magic abuses nature-spirits (aka elemental beings gnomes, elves, nymphs, etc.) as its slaves. Through its dark means of spells, killings, acts of war, etc. it can capture these nature spirits and make then their slaves. This is possible because nature spirits are actually a kind of cleric beings which normally do as they are instructed by the angels, because they literally are the thoughts of those angels.
Black magic filters spiritual secrets out of those nature spirits and the spiritual world through its dark means and uses the earth purely for its earth-directed and egocentric goals of lust, power, control, money, etc. Therefore it fixates the life-forces to the utmost heavy degree into the physical world so the spirit-light cannot work through it any more.
Black magic also craves to gather spiritual insights without any effort and so without going through any spiritual development – most definitely not a development towards freedom, love and spiritual morality.
Black magic abuses and manipulates the human spirit, soul and life-forces and physical bodies, which can even go as far as carrying out severely inhumane actions on people such as terrorizing, mind-control, torture, horrendous satanic rituals, insane pedophilia and killing.