Still, Karna could not bring himself to refuse any gift that was asked of him. Hence he cut off the earrings and armor with which he was born and gave them to the brahmana. Indra, the king of gods, was filled with surprise and joy. After accepting the gift, he praised Karna as having done what no one else would do, and, shamed into generosity, bade Karna ask for any boon he wanted. Karna replied: "I desire to get your weapon, the Sakti, which has the power to kill enemies." Indra granted the boon, but with a fateful proviso. He said: "You can use this weapon against but one enemy, and it will kill him whosoever he may be. But this killing done, this weapon will no longer be available to you but will return to me." With these words Indra disappeared. Karna went to Parasurama and became his disciple by representing to him that he was a brahmana. He learnt of Parasurama the mantra for using the master weapon known as Brahmastra. One day Parasurama was reclining with the head on Karna's lap when a stinging worm burrowed into Karna's thigh. Blood began to flow and the pain was terrible. But Karna bore it without tremor lest he should disturb the master's sleep. Parasurama awoke and saw the blood that had poured from the wound. He said: "Dear pupil, you are not a brahmana. A kshatriya alone can remain unmoved under all bodily torments. Tell me the truth." Karna confessed that he had told a lie in presenting himself as a brahmana and that he was in fact the son of a charioteer. Parasurama in his anger pronounced this curse on him: "Since you deceived your guru, the Brahmastra you have learnt shall fail you at the fated moment. You will be unable to recall the invocatory mantra when your hour comes." It was because of this curse that at the crisis of his last fight with Arjuna, Karna was not able to recall the Brahmastra spell, though he had remembered it till then. Karna was the faithful friend of Duryodhana and remained loyally with the Kauravas until the end. After the fall of Bhishma and Drona, Karna became the leader of the Kaurava army and fought brilliantly for two days. In the end, the wheel of his chariot stuck in the ground and be was not able to lift it free and drive the chariot along. While he was in this predicament, Arjuna killed him. Kunti was sunk in sorrow, all the more poignant because she had, at that time, to conceal it.