Ask any person, whatever their religion, what or who is the biggest source of evil in the world and they will undoubtedly say the devil, satan, iblis, etc. What the Quran says about this ‘idea’ is that it has no control over you! It has no power to corrupt you, mislead you, or do anything out of the ordinary which you cannot do yourself (hence, no supernatural occurrences); in nutshell:-
14:22 Satan (their selfish desires) will disown them after the Judgment has been issued, "Verily God promised you a true promise; and I promised you and failed you. And I had no power over you except that I called unto you and you obeyed me. So blame me not, blame yourselves. Neither can I help you, nor can you help me. I refuse to accept that you worshiped me ever." Surely, for those who displace trust with betrayal is a painful doom.
14:23 And those who attained belief and increased human potential, will be admitted to the Gardens underneath which rivers flow, therein abiding by their Lord’s Leave. Their greeting therein is, “Peace!”
Satan cannot do anything to influence you by way of ‘nazzar’ (evil eye), magic spells etc. so how can anyone like Brother Muhammad” from Nigeria (a local Muslim witchdoctor in my area) affect you? He specializes in protecting Quranic verses spells and star signs, very Uranus!
A person believing in sorcery is self deluded, either through their own beliefs or following others. In a limited number of cases it is a result of some sort of mental health problem.
There is a good case to be made for arresting charlatans who propagate and make money from the gullible, charging them with spreading corruption in the land. The death sentence is extreme and un-Islamic, but a suitable punishment should be there as well as a deterrent for others not to go down that path.