Brahmastra

The Brahmastra (IAST: Brahmāstra) is an astra (supernatural weapon) that is one of the most destructive, powerful, and irresistible weapons mentioned in Hinduism. Only Parashurama, Rama, Meghanada, Bhishma, Drona, Karna, Ashwatthama, Arjuna, and Lakshmana possessed the knowledge to invoke this weapon. It was created by Brahma along with its more powerful variants Brahmashirā astra, Brahma danda, and Bhargavastra.

Description
It is termed as a fiery weapon that creates a fierce fireball, blazing up with terrible flames and countless horrendous thunder flashes. When discharged, all nature including trees, oceans, and animals tremble. The sky surrounds with flame, glaciers melt, and mountains shatter with copious noise all around.

When used, the Brahmastra which is person-centric can destroy a powerful enemy if they do not possess an alternate counter weapon. If it is Brahmashirā astra, it causes collateral damage to every useful resource in a given area and prevents even a single blade of grass from ever growing in that area again. It is mentioned that there would be no rainfall for 12 Brahma years (12 Brahma years = 37.32 trillion human years) and climate conditions will worsen. The strike of the Brahmashirā astra will eventually destroy everything.

When Ashwatthama hurled the Brahmashirā astra against Arjuna, the Pandava countered by invoking the same weapon; to prevent widespread destruction, Narada and Vyasa stood between the two astras, ordering the two warriors to withdraw their weapons. Arjuna, out of nobility, did so; Ashwatthama, however, out of anger, refused to recall the astra and rather directed it to Uttarā's womb to kill the unborn Parikshit in an attempt to produce some level of damage to his opponents, but Krishna intervened and saved the child. Ashwatthama was made to surrender the gem on his forehead and cursed by Krishna that he will roam in the forests until the end of time with blood and pus oozing out of his injuries as he cries for death, but death would not meet him.

Brahmashirā Astra
The Brahmashirā Astra or Brahmashirsha astra (Brahma's 4 head weapon), manifests with four heads of Brahma at the front and is four times stronger than the normal Brahmastra. Arjuna, Drona, Karna, Ashwatthama, and Bhishma were among who possessed this knowledge in Mahabharata. It is also able to annihilate someone's existence from the past, present, and future, making their existence impossible to be imagined and because they did not exist and will not exist, it is impossible for them to ever exist in any facet or form in any meaningful way.

Brahma Danda
The Brahma Danda (Brahma's rod) or also known as Brahmanda, is a weapon of self-defence, created by Brahma. It is only to be possessed by ascetics and its powers are dependent on its owner. The weapon is a rod capable of absorbing any incoming attack towards its owner. When Vishvamitra, in a fit of anger, unleashed the Brahmastra onto Vasishtha, it was his Brahmanda that protected him from the lethal weapon.

Literature
There are numerous instances within Sanskrit theological scriptures where the Brahmastra is used or its use is threatened, including:


 * Kaushika (who later became Brahmarshi Vishvamitra) used it against Maharishi Vasishta, but the Brahmastra was swallowed by Vasishta's Brahma danda.
 * Indrajita used the Brahmastra against Hanuman, but Hanuman survived because of the boon previously given to him by Brahma.
 * In the Ramayana, a Brahmastra is used by Rama several times: once against Jayanta when he hurt Sita, against Maricha in their last encounter, and finally the Brahmastra was used in the last battle with the rakshasa emperor Ravana. According to the Ramayana, the weapon was also aimed at Varuna (the sea god) to carve a path out of the sea, such that Rama's army could march towards the island of Lanka. However, as Rama loaded the weapon, Varuna appeared and offered to assist the king in crossing the ocean. This incident is mentioned in Yuddha Kanda 22 Sarga, Verse 31.