Varunastra
The Varunastra (Sanskrit: वरुणास्त्र, romanized: Varuṇāstra, lit. 'Astra of Varuna') is the signature celestial weapon (astra) of the Hindu god of the hydrosphere, Varuna. It is described as a water weapon (a storm) in Indian scriptures, said to be amorphous like water and thus able to assume any weapon's shape.