'To be avenged seventy and seven fold' denotes damnation.

In Genesis 4:15, vengeance signifies a sacrilege, and condemnation for it. (Arcana Coelestia 392)

In Deuteronomy 32:35, this signifies the genuine truth that the Lord is love and mercy itself. (Doctrine Regarding Sacred Scripture 94)

In Psalm 94:1, this signifies judgment on the Jews because they had destroyed the church. (The Inner Meaning of the Prophets and Psalms 344)

In Psalm 99:8, this signifies that the Lord is the Redeemer although it appears that He punishes. (The Inner Meaning of the Prophets and Psalms 349; Doctrine Regarding Sacred Scripture 94)

In Isaiah 59:17, this signifies the truths by which the Lord fought with the hells. (Apocalypse Explained 395[13])

In Isaiah 34:8, this signifies the Last Judgment and the condemnation of people who, by falsities and evils, have destroyed the truths of the church. (Apocalypse Explained 850[16])

(Odkazy: Arcana Coelestia 432-444, Genesis 4:24)

432. Verse 24 For sevenfold will Cain be avenged, and Lamech seventy-sevenfold.

This means that men annihilated the faith meant by 'Cain', which it was utterly forbidden to violate; that at the same time they annihilated charity, which born by means of faith, something even more inviolable; and that on account of this, condemnation followed, which is 'being avenged seventy-sevenfold'.