The Divine Discus
Cakra (Sanskrit: wheel/discus; Tamil: āzhi) is the spinning discus weapon held by Bhagavān Viṣṇu in one of His four principal hands. The specific cakra of Viṣṇu is called Sudarśana ('of beautiful vision') — a divine weapon-being of immense power that executes the Lord's will to protect the righteous and destroy evil.
Sudarśana as a Being
In the Pañcarātra tradition, Sudarśana is not merely a weapon but a divine being — a vyūha emanation who can be worshipped independently. Sudarśana shrines exist within major Śrī Vaiṣṇava temples (Śrī Raṅgam, Tirumalai), and the Sudarśana Homam (fire ritual) is performed for protection and removal of obstacles.
At Pañca-saṃskāra
The heated cakra mark branded on the right shoulder at initiation signifies: 'I am under the protection of Sudarśana; I bear the Lord's mark.' Together with the śaṅkha on the left shoulder, the two marks declare the complete dedication of the devotee's body to Bhagavān.