"Black magic" is a lie. Nothing you "saw" was true. Also, you can't sell your soul. It isn't yours to sell. Devils will try to convince you that you sold something, but, you can't. Devils come to deceive you, and then painfully destroy your life. So avoid all that.
.
Instead, believe in Jesus for eternal life, and then ask Jesus to bless your life, and He will :)
The truth is that death leads to immediate heaven or hell, depending only on whether the person believed in Jesus for eternal life, or not.
.
Jesus loves you and wants to bless your life freely :) Most of all, Jesus wants you with Him forever, and not in hell. The truth is that every belief except one will lead to eternal torment in the lake of fire for every person. Because nothing pays for our sins except the death and blood of Jesus, the sacrifice of Jesus that is already accomplished by Him . Jesus loves you! The truth is that Jesus is God, and Jesus died on the cross to pay for all of our sins in full, and then Jesus resurrected from the dead. Nothing else pays for our sins, not works, not deeds, not religions. So the only way to heaven and to avoid hell, is by believing in Jesus for eternal life (John 6:47), without adding any of your own works (Romans 4:5). Believe in Jesus to take you to heaven, and you will be in heaven, no matter what, guaranteed. That easy, thanks to Jesus! Tell Jesus that you thank Him that you will be with Him in heaven when you die, because you believe in Jesus! It is too late to be saved, after death
You can't use magic. Your imagination is getting the better of you. You can't "sell your soul" - your "soul" is you, your Id, Ego, conscious, subconscious. It is every memory, experience, emotion, or thought you have ever had. Your "soul" is you. If you could "sell your soul" your body would be a mindless zombie, because you wouldn't be in it - and that's impossible, because everything you are is electrobiochemically encoded in your brain cells.
Magic is not real. Not white, black, grey, red, blue, or green. There are no "schools" of magic. No book, item, ritual, or being can grant you imaginary "powers" - if that was so then the U.S. Government would have these people under lock and key and would be using them as living weapons. No amount of chanting or performing made up "rituals" can alter, affect, or cause any documentable changes or results in Reality.
There is no nebulous energy field capable of altering or changing reality or the physical world. If there was such a energy source we would see the results and effects, much the same way we can see the results of electricity – consistent, repeatable, objective effects. Energy follows repeatable patterns that can be observed, documented, and predicted. No amount of wand-waving, circle-drawing, crystal-gazing, candle-lighting, athame-wielding, incense-burning, spell-chanting ritual nonsense can cause a single objective effect.
If “magic” was real, and the ability to use it was hereditary, then at the least it would be passed down via Mendelian genetics, expressing 25% of the time – meaning that 1.7 BILLION of the human population would carry the gene. Even if a thousandth of that number expressed the trait actively it would mean over 1.7 MILLION “magic-users” running around and we would have objective, documentable evidence of the existence of “magic”. No such evidence exists. There is no energy field capable of altering reality on a whim.
Sorry to make people face the facts, but not one "spell", of any "type" can cause even the smallest objective alteration to Reality. Coincidental results are nothing but wishful thinking and rationalization.
Rhymes are not spells. If any random collection of rhyming words created magical effects, then ALL songs would be causing magical havoc anytime anyone sang them with emotion and conviction.
Words have power, yes – the power to cause us to think, to choose, to decide, to consider, to change our minds. They do not cause “magic”.
There are no such things as “magic spells”.
If there were we would see their effects everywhere, everyday. People all over the world would be causing near random effects everywhere just from talking, or screaming, or arguing, or singing.
Words are not magic. No amount of emotion, feeling, conviction, willpower, anything – can cause any collection of rhyming or non-rhyming words to create any kind of magical effect or result. Magic isn’t real.
If magic was real, like any form of energy we would be able to measure its effects by observation, documentation, testing/experimentation, and comparison of accumulated results for consistency, like any real form of energy.
Electricity is real – even though we cannot see it, because it acts the same way, consistently, according to the laws of Energy, and produces the same results over and over and over and over again ad infinitum. If I flip my light switch 1 million times, the light comes on everytime, unless the power is off or my bulb burns out.
No evidence exists to even support a hypothesis of “magic”, let alone a working theory. None. And not ONE person giving me thumbs down can provide objective arguments supported by factual data to refute any point I have made. Magic is not real.
Well, if you sell your soul to lengthen your life, your black magic didn't work since you won't die when you foresaw it. Isn't that going to be a problem. I mean if you see into the future, you cannot change the future, otherwise you did not really see into the future.
All those problems aside: Address the empty air three inches behind your left earlobe. Make sure there is really nothing there. Then say: most venerated Demon of the august places, please accept my scrawny soul in exchange for a life which will last as long as it pleases the heroic administrators above. Bang your head not to hard three times with your left hand. Then fall to your knees and kowtow until you feel a little breeze or something like that. Then you are done and you have donated your soul to a unknown purpose. You can continue your life as usual, but if you ever try black magic again, it's going to backfire. You cannot do magic of any type without a soul.