When Kaṁsa spoke in this way, Lord Kṛṣṇa became very angry with him, and within a second He jumped onto the high dais of King Kaṁsa. Kaṁsa was prepared for Kṛṣṇa’s attack, for he knew from the beginning that Kṛṣṇa was to be the supreme cause of his death. Kaṁsa immediately unsheathed his sword and prepared to answer the challenge of Kṛṣṇa with sword and shield. As Kaṁsa wielded his sword up and down, hither and thither, Lord Kṛṣṇa, the supreme powerful Lord, caught hold of him with great force. The Supreme Personality of Godhead, who is the shelter of the complete creation and from whose lotus navel the whole creation is manifested, immediately knocked the crown from the head of Kaṁsa and grabbed his long hair in His hand. He then dragged Kaṁsa from his seat to the wrestling dais and threw him down. Then Kṛṣṇa at once straddled his chest and began to strike him over and over again. Simply from the strokes of His fist, Kaṁsa lost his vital force.
To assure His parents that Kaṁsa was dead, Lord Kṛṣṇa dragged him just as a lion drags an elephant after killing it. When people saw this, there was a great roaring sound from all sides as some spectators expressed their jubilation and others cried in lamentation. From the day Kaṁsa had heard he would be killed by the eighth son of Devakī, he was always thinking of Kṛṣṇa with His wheel in hand, and because he was very much afraid of his death, he was thinking of Kṛṣṇa in that form twenty-four hours a day, without stopping—even while eating, while walking and while breathing—and naturally he got the blessing of liberation. In the Bhagavad-gītā it is stated, sadā tad-bhāva-bhāvitaḥ: (BG 8.6) a person gets his next life according to the thoughts in which he is always absorbed. Kaṁsa was thinking of Kṛṣṇa with His wheel, which means Nārāyaṇa, who holds a wheel, conchshell, lotus flower and club.
According to the opinion of authorities, Kaṁsa attained sārūpya-mukti after death; that is to say, he attained the same form as Nārāyaṇa (Viṣṇu). On the Vaikuṇṭha planets all the inhabitants have the same bodily features as Nārāyaṇa. After his death, Kaṁsa attained liberation and was promoted to Vaikuṇṭhaloka. From this instance we can understand that even a person who thinks of the Supreme Personality of Godhead as an enemy gets liberation or a place in a Vaikuṇṭha planet, so what to speak of the pure devotees, who are always absorbed in favorable thoughts of Kṛṣṇa? Even an enemy killed by Kṛṣṇa gets liberation and is placed in the impersonal brahmajyoti. Since the Supreme Personality of Godhead is all-good, anyone thinking of Him, either as an enemy or as a friend, gets liberation. But the liberation of the devotee and the liberation of the enemy are not the same. The enemy generally gets the liberation of sāyujya, and sometimes he gets sārūpya liberation.
Kaṁsa had eight brothers, headed by Kaṅka, all of them younger than he, and when they learned that their elder brother had been killed, they combined together and rushed toward Kṛṣṇa in great anger to kill Him. Kaṁsa and his brothers were all Kṛṣṇa’s maternal uncles, brothers of Kṛṣṇa’s mother, Devakī. When Kṛṣṇa killed Kaṁsa He killed His maternal uncle, which is against the regulations of Vedic injunctions. Although Kṛṣṇa is independent of all Vedic injunctions, He violates the Vedic injunctions only in inevitable cases. Kaṁsa could not be killed by anyone but Kṛṣṇa; therefore Kṛṣṇa was obliged to kill him. But as far as Kaṁsa’s eight brothers were concerned, Balarāma took charge of killing them. Balarāma’s mother, Rohiṇī, although the wife of Vasudeva, was not the sister of Kaṁsa; therefore Balarāma took charge of killing all of Kaṁsa’s eight brothers. He immediately took up an available weapon (most probably the elephant’s tusk which He carried) and killed the eight brothers one after another, just as a lion kills a flock of deer. Kṛṣṇa and Balarāma thus verified the statement that the Supreme Personality of Godhead appears in order to give protection to the pious and to kill the impious demons, who are always enemies of the demigods.