Giantia

The Legion of Super-Creatures from Giantia attack Superman in this cover by Curt Swan & George Klein

A far-distant planet revolving about a red sun, a gigantic “leper world .. . shunned because of the terrible monsters which inhabit it”, which has become the adopted home of three death-worshipping “madmen” from another planet, the sole survivors of a “space blight” which decimated life on their world, who have entered into a “solemn vow” to “bring death to 100 other worlds”, including Earth, as lunatic compensation for the death of their own world, and then to blow themselves and all of Giantia to kingdom come after performing “a final ceremony in honor of death!” The aliens do indeed destroy themselves in a planet-shattering holocaust, and Superman, helpless before the awesome space monsters which they have dispatched to destroy the Earth, only succeeds in stopping the monsters and saving Earth by virtue of a fortuitous accident (Act No. 326, Jul 1965: “The Legion of Super-Creatures!”).