I finally destroyed my life-long enemy -- only to become a mass murderer of monstrous magnitude. 
Superman #248 is an issue of the series Superman (Volume 1) with a cover date of February, 1972.
Synopsis for "The Man Who Murdered the Earth!"
Lex Luthor created a Galactic Golem to destroy Superman, un-ironically comparing himself to Victor Frankenstein. He used a Galactic Cannon to saturate Superman with Galactic Matter; and the Golem was attracted by it and attacked Superman. Lex watched as Superman and the Golem came together and detonated, and believed that he had destroyed all life on Earth as a result of their titanic battle.
Afterwards, Superman reappeared and had to save Lex himself from the Golem, as he had changed the vibrational frequency of every living thing on earth to shunt them into another dimension. Despite Superman's return, Lex Luthor was still glad to see that life returned to the Earth.
Appearing in "The Man Who Murdered the Earth!"
Featured Characters:
Supporting Characters:
Antagonists:
- Galactic Golem (First appearance)
- Lex Luthor
Other Characters:
- Victor Frankenstein (Mentioned only)
Locations:
- Meteor Swarm
- Metropolis
- Luthor's Lair
- Metropolis Open Golf Classic
- Mountain
- WGBS-TV Studio
- Moon
Items:
- Galactic Cannon
- Galactic Matter
- Statue of Superman
Synopsis for "All in the Mind!"
A Kryptonian archaeological team lead by Min-Tor, discovered a record of how mutant children were exiled from the land of Erkol during a war with Xan. Lead by Jan-Ar and Sala, the mutants were the only survivors of that conflict and they founded the city of Kryptonopolis.
The children were big-lobed, no-thumbed and silent and were thought to be unthinking; though they developed powers of telekinesis and telepathy and would have been critical to Erkol's war effort, had Erkol's Council of Elders realized this before it was too late.
Appearing in "All in the Mind!"
Featured Characters:
- Jan-Ar
- Sala
Supporting Characters:
- Lan-Nu
- Min-Tor
Antagonists:
- Erkol Council of Elders
Other Characters:
- Frippe
Locations:
- Rao
- Krypton
- Dandahu Ocean
- Erkol
- Fire Falls
- Kryptonopolis
- Rainbow Valley
- Scarlet Jungle
- Sea of Eiu
- Xan City
- Krypton
Items:
- All-Element Bomb
- Thought-Wave Globe
Vehicles:
- Sun-Disk
Synopsis for "Muto Versus the Man of Tomorrow!"
This story is reprinted from Action Comics #339.
The Superman of 2966 escapes a water trap set for him by Muto with the help of three android children. He then helps the Atlanteans defeat one of Muto's lieutenants threatening Atlantis. Muto then uses a growth ray to enlarge the people of Metropolis to gigantic height. Superman restores them to normal before his confrontation with Muto. Having deduced Muto's weakness, Superman is able to open a space-warp capable of sending Muto back to his home dimension, and hopes that the villain never returns.
Appearing in "Muto Versus the Man of Tomorrow!"
Featured Characters:
Supporting Characters:
- Jay L-3388/Jay Senohl (future descendant of Jimmy Olsen)
- Lyra 3916 (future descendant of Lois Lane)
Antagonists:
- Muto
- Von-Don (Muto's lieutenant)
Other Characters:
- Three Android Children
- Various Atlanteans
Locations:
- Metropolis of 2496/2966
- Muto's Underwater Base
- Weapons World
Items:
- Colossal Grapple
- Expander Ray
- Helium Bomb
Vehicles:
- Muto's Rocket Ship
Notes
- The Man Who Murdered the Earth! is reprinted in Lex Luthor: A Celebration of 75 Years.
- All in the Mind! is reprinted in:
Trivia
- The Galactic Golem is a reference to both the literary Frankenstein's Monster and the Golem of folklore; where he is de-animated by touching his forehead and removing a letter - an aleph - to return him to the dead; as Superman attempted to do.
- The names Jan-Ar and Sala closely resemble those of Jan Arrah and Salu Digby of the Legion of Super Heroes.
See Also