When Arjuna used the Anjalika astra on weaponless Karna, who was still trying to lift the sunken chariot wheel, Lord Krishna found that Karna was still alive even though seriously wounded. Lord Krishna found that Dharma-devata, the goddess responsible for protecting Dharma (righteousness), is guarding Karna against death and resisting every arrow sent by Arjuna. Krishna and Arjuna found it was impossible to kill Karna as the goddess was protecting Karna personally. Lord Krishna explained to Arjuna that the Dharma-devata herself was protecting Karna from death because of the massive good merit Karna earned by giving charity during his lifetime and it was impossible even for Lord Shiva to kill Karna. Krishna said wherever Dharma is present, there is victory, and this time Dharma was with the side of Karna. So Krishna went down from his chariot and appeared as a Brahmin and asked for Karna's punya or merit to him as charity. Karna gave his entire merits as charity to the Brahmin in the form of his blood, and once Karna gifted his life's merit to him, Krishna rewarded Karna with the view of Krishna's Vishwaroopa. Krishna told that only this way it was possible to kill Karna and when Karna gave away his life's merit to Krishna, Dharma-devata disappeared. Karna asked Krishna to cremate him in a virgin land where nobody else is present. Then Krishna went back to his chariot and asked Arjuna to take the kill shot on Karna. Later Krishna himself did the cremation of Karna at Karnaprayag.