A Tantric mantra is one that is used in puja (worship) and to help resolve problems. There is a wide range of Tantric mantras, each designed to resolve a particular issue. Tantra is a term used to describe the esoteric mystical and ritualistic religious traditions typically associated with Shaktism in the Hindu tradition and Vajrayana in Buddhism.
Rudrayamala Mantra is a powerful mantra used in Tantra. This mantra is a big deal. You probably should not use it at all, unless you feel it is unavoidable.
The Rudrayamal Tantra mantra for destroying enemies is one of the most powerful black magic mantras. People have used this (and similar mantras) for thousands of years to destroy enemies and to crush the competition.
This is the most powerful Maran and Uchchatan Mantra. Maran means to kill and Uchchatan means to remove from your life permanently. This mantra is a Rudra Mantra [fierce mantra] from the Rudrayamala Tantra.
Om visvaaya naam gandharvalochni naami
lousatikarnai tasmai vishwaya swaha ll
ॐ विस्वाय नाम गंधर्वलोचनी नामी लौसतिकरनै तस्मै विश्वाय स्वहा ll
HOW TO DO IT
The Siddhi [mastery] over this mantra is acquired by standing naked in water and reciting this mantra 1000 times.
After this one has to perform Dashansh Havan.This means 1/10th of the total recitations, which are 100 Havans.
This Havan is picking up some water in your folded palms and releasing it back into the water while reciting the mantra. This has to be done 100 times.
A Havan means an offering which is in this case to the presiding deity of this mantra. All the time while doing this Sadhana [practice] one has to keep in mind the name/names of the enemy/enemies for whom this is being done.
This knowledge should be used with caution and for purposes of protection of the self and family.