Sudarshan

When an infinite number of arrows had been cut to pieces, and the weapons began to be exhausted, Kṛṣṇa resolved to put Bāṇa to death. The destroyer of the demon host therefore took up his discus Sudarśana, blazing with the radiance of a hundred suns. As he was in the act of casting it, the mystical goddess Koṭavī, the magic lore of the demons, stood naked before him. Seeing her before him, Kṛṣṇa, with unclosed eyes, cast Sudarśana, to cut off the arms of Bāṇa. The discus, dreaded in its flight by the whole of the weapons of the demons, lopped off successively the numerous arms of the Asura.

Vishnu Purana Book 5 Chapter 33