Is it permissible for a man to return to his first wife, whom he divorced three times, knowing that one of the divorces occurred during her menstrual period, and that the man believes he was under sorcery at the time of the divorce?

A person does not have the right to justify their bad actions, such as divorcing their wife unjustly, by claiming magic, evil eye, and the like. This is because these matters do not negate free will unless the person is in a state where they are unaware of what they are doing, and only then would they have an excuse. If you have divorced your wife with three pronouncements, she becomes unlawful for you until she marries another man out of genuine desire, not for the purpose of making her lawful for you again. As for divorce during menstruation, it is valid according to the majority of scholars, though the one who performs it incurs sin. Regarding divorce under duress, it does not occur with valid, Sharia-compliant coercion, but the nature of the pressures you faced must be clarified. It is advisable to consult the Sharia court in your country to resolve the dispute, and treatment for magic is through ruqyah (Islamic incantations).