There are several Vidyas within the Tantric tradition which are said to dispel or destroy black magic. Many serve as a protective aspect for sadhaks against obstructions from all class of beings. However, there are several areas of misunderstanding both as it relates to black magic and how the Vidyas which dispel it work. When we speak about black magic, the image it evokes is of some nefarious character doing a ritual to harm, and while this can be the case, this is not the type of black magic that most people encounter. However, most people do encounter intrusive energy (i.e. black magic) on a daily basis in the form of negativity, projection, ill will, and hurtful intent. There are also more energetic aspects which may lack intent, but are none the less impactful. We have all experienced being around a person who is "nice" but just is exhausting to encounter, and others whose energy is just kind of sticky and lingering. In fact, most forms of negativity lack personal intent (i.e. "against you") but are no less impactful to the environment and people in it. When an immature person is "having a bad day", then everyone around them are about to also, and most people are immature. So when we hear about how a certain Vidya destroys black magic, we should understand it in the context of our day to day environments and encounters. But more than this, we should understand it as it applies to ourselves and dispelling our own black magic patterns. Whomever one considers their largest "enemy" or irritant is likely someone that is only encountered occasionally, but one has to be with themselves constantly. In fact, people are constantly doing black magic against themselves, and this creates a point of resonance that makes one receptive to the obstruction projected from others. Therefore, the main focus of working with a Vidya which "dispels and destroys black magic" is to allow the energy of the Devata to illuminate and destroy those patterns in ourselves. Once we are no longer practicing black magic (on ourselves and on our environments), then in large measure we are protected from it. The protection comes both in the form of view and energetics with various levels understanding at play. For example, the wisdom of "not minding another business" is a view which understands that another person's "garbage", even if you are included somehow in it, belongs to them, and you are under no obligation to "pick it up". Of course though, wisdom doesn't always protect energetically, so while this understanding would allow one to "not take to heart" other peoples garbage/projections, it may still give an energetic residue which needs to be processed. This is where working with certain Vidyas helps, as once assimilated, even energies don't penetrate. However, as long as one's view includes notions of self and other, there is still vulnerability, and paradoxically it is by stepping into complete vulnerability that one comes to the wisdom that can't be harmed. When we understand notions of self to be ignorance and others to be empty, then as spacious awareness, not only does projected energy have nowhere to "land", it has nowhere to come from. Negative energies and projections are dispelled at the moment they arise. This is the pure wrathful manifestation of the protector Vidyas. However, even with the highest wisdom and energetic integrity with these Vidyas, various obstructions arise, and this is where we test the purity of our view. As many saints have said, if you cut the power on a locomotive, it will still continue its movement based on momentum. Just so, even in wisdom, life will continue to move, and obstructions will arise. However, the wise will not only take responsibility for obstructions (as karma), but welcome them as expedients. Greater than this, when obstructions are seen not only as indicators of wisdom display, but not different than it, then everything is the path. When wise people with expansive minds do the works of Vidyas which work against black magic, they do so with nobel intent. It is not done "against" people, but for them (in a true way). When a wise person sees another filled with negativity and harmful intents, they do not see it as "them" but rather as something harming them (and obscuring their true nature). Indeed, the greatest kavach opposing black magic is purity of heart and intention. I recently read an account of a Tantric master from Tibet (regrettably I cannot remember his name) which not only touched me but speaks to purity of heart/intent as the ultimate kavach against black magic. It appears this master was getting harassed by a certain powerful spirit. This same spirit was said to have annoyed and shorten the life span of both Dodrupchen and Dudjum Lingpa (These were both spiritual giants, which illustrates the point that even in wisdom obstructions can arise. Moreover, they were both accomplished in vidyas which are very potent in dispelling negative forces. This fact speaks to the power of how this spirit was ultimately tamed.) Finally, at a time when this spirit was being particularly intrusive and annoying, this tantric master thought with all his heart "I will never abandon you, I will never abandon you, I will guide you to liberation". Such a pure intention toward a spirit doing black magic, and the spirit melted in the face of such love.