Brahmastra

It was considered the deadliest weapon. It was said that when the Brahmastra was discharged, there was neither a counter attack nor a defense that could stop it, except byBrahmadanda, a stick also created by Brahma. The Brahmastra never missed its mark and had to be used with very specific intent against an individual enemy or army, as the target would face complete annihilation. It was believed to be obtained by meditating on the Creator in the Vedas, Lord Brahma; it could only be used once in a lifetime. The user would have to display immense amounts of mental concentration. According to ancient Sanskrit writings, the Brahmastra is invoked by a key phrase or invocation that is bestowed upon the user when given this weapon. Through this invocation the user can call upon the weapon and use it via a medium against his adversary.

Since Brahma is considered the Creator in Sanatana Dharma, it is believed by Hindus that Brahmastra was created by him for the purpose of upholding Dharma and Satya, to be used by anyone who wished to destroy an enemy who would also happen to be a part of his (Brahma's) creation. The target, when hit by Brahmastra, would be utterly destroyed. Brahma had created a weapon even more powerful than the Brahmastra, called the Brahmashira. The Brahmashira was never used in war, as it was four times powerful than the Brahmastra, i.e Fourth power square, as the name suggests, since Brahma has Four Heads. Only Arjuna and Ashwatthama possessed the knowledge to summon the Brahmashira.