A golden rule for anyone that wishes to practice black magic is that such a person should be capable enough to pursue it. The person should be strong enough to practice it, not only physically but also mentally. Actually, the mental strength factor is more important than the physical strength factor when a question arises regarding black magic.
Working with black magic is like dealing with such persons who affect your life deeply and maybe that will last with you till your very end. So before performing black magic a person should be mentally strong enough to control the ill-effects of black magic, he should be (extremely) self-conscious, mentally stable, should know that he has to use the power in well being of others; it should not happen that due to your geed, fear, emotional weakness, etc. entities governing dark powers shall start governing you.
It is very necessary that “you” should have control over all your body chakras rather than letting dark powers gaining control over them. It is not an easy task for all magic enthusiasts to perform black magic, sometimes you have to be ready to sacrifice more than what you expect to gain.
“what happens” actually depends on the black magic practitioner. If he knows all the ill effects of misusing the powers gained by practicing black magic and then uses it for his own greed or to harm others, then definitely karma will play a role and render due justice. It is never advisable for any person to perform black magic if he is a common man, because if any bad occurrence does take place then the chances of harming his loved ones along with himself are extremely high.
So here comes the tricky part. Once the magic (black or white) spell is cast, the practitioner will say the spell worked if a good event (white magic) or a bad event (black magic) occurs. If the practitioner is sincere, they will believe the spell worked. The other potential way the spell will work is if the practitioner has information or the power to physically make an event happen or more likely to happen.
The true test can occur if the practitioner of magic (black or white) can accurately, with details and no prior knowledge define the results of the spell, cast the spell, then measure the results of that same spell. Finally, the results must hold up to scrutiny.
Science works this way. The scientist makes a prediction (creates a hypothesis). The scientists create a spell (experiment). The scientists cast the spell (runs the experiment). The scientists check to see if the spell (experiment) worked based on the predictions (hypothesis). The scientist puts the results of the spell (experiment) out for other scientists to evaluate.
Some practitioners of magic (black or white) fail to follow this system. Each time such practitioners of magic attempt to follow this system, their spells fail. The spells only work through confirmation bias.
Em Hotep - Patrick Gaffiero