Born with Kavasam and Kundalam (Armour and ear-rings), and bequeathed as a gift from the Sun God to an unwed Kunti (M. V. Rajamma), Karnan is abandoned so as to prevent embarrassment for her. He is set afloat in the Ganga, rescued and adopted by a charioteer, who is employed withDhritarashtra, the blind king. Years later, the now-grown up Karnan (Sivaji Ganesan) realizes that the charioteer is his foster father only, thus heartbroken. He however masters archery and challenges Arjun (R.
Muthuraman) at a contest. When Karnan is insulted on account of his birth,Duryodhan (S. A. Ashokan) defends him and accepts him as his partner. Karnan is eventually crowned the king of Anga. At one time, Lord Indra, the rain god and king of heavens, disguised as an old Brahmin, goes to Karnan and asks for his Kavasam and Kundalam indaanam (donation). Indra was apprehensive that Karnan, by virtue of his phenomenal skills as a warrior, may be able to overwhelm Arjun.
He therefore asked for this gift so as to reduce his strength. Karnan had been cautioned by the Sun God that Lord Indra was going to make some such move. But Karna is so large hearted that he cannot refuse anyone. Knowing fully well, that Indra was playing a trick on him disguised as a Brahmin, he yet parts with his Kavasam and Kundalam, which were parts of his body since birth and which made him invincible. Lord Indra is taken aback at Karnan’s capacity to give away anything asked for.
He tells that what Karnan has done today, no ordinary mortal could have done. Immensely pleased with Karnan’s generosity, Indra lets him ask for any varam (wish). Karnan asks Indra to kindly give him the weapon Shakti which has the potential to destroy any enemy. Lord Indra gives Shakti to Karnan with the proviso however that he could use it only once and that thereafter the weapon shall return to Lord Indra.