Personal Info:
Real Name: Unknown
Also Known As: Super-Doomsday, The Last Knight of Tomorrow
Place Of Birth: Earth-45
First Appearance: Action Comics Vol.2 #9 (2012) Modern Age Villain
Known Associates: Vyndktvx, Kryptonite Man, Dr. Xa-Du, Erik Drekken, Metalek, Nimrod the Hunter, Susie Tompkins
Group Affiliation: The Anti-Superman Army, Overcorp
Base Of Operations: Mobile
Grudges: Superman
Creators: Grant Morrison and Gene Ha
Enhanced Abilities: Superdoom's strength, durability and endurance are variable, based on the collective belief in the people of the Multiverse in what it represents: by the time it reached Earth 23, its abilities were approximately equal to that Earth's local Superman.
Size Alteration: A living franchise that "gets bigger and bigger the more you think of it", Superdoom increases in size and strength as more people come to believe in what it represents.
Body Armour: Superdoom's armour shields him from Kryptonite attacks.
Energy Projection: Superdoom has been shown to emit beams from its eyes capable of harming Superman.
Dimensional Travel: Superdoom uses Transmatter Cubes to travel between parallel universes.
On Earth-45, after a trip to Tibet, Clark Kent and his friends Lois Lane and Jimmy Olsen built a machine utilizing sound vibrations to turn thoughts into reality, and brainstormed a possible use for it - creating a thoughtform named Superman, "a thought-powered redeemer capable of saving the world". Unfortunately, they had to sell the device and the idea to Overcorp, a business entity with a secretive CEO, who took the Superman concept and twisted it into something at once more brutal and simultaneously "toyetic" in order to achieve maximum public appeal - Superman, the Last Knight of Tomorrow, better known to its victims as Superdoom.
A self-described "killer franchise", Superdoom wasted no time in becoming the pre-eminent superhuman of its world. Its distinctive logo became a global phenomenon, a popularity used by Overcorp to effectively take control of the planet. Superdoom itself, motivated by its corporate directives to eliminate all possible forms of competition, entered the Bleedspace, both to hunt down its creators (who had learned that their machine allowed transportation between universes, and had fled in search of help), and to slaughter all other Supermen.
After ravaging countless parallel planets and butchering (and in at least one case subsequently devouring) numerous Supermen and Superman-analogues, including Optiman of Earth 36 and the Chibi Superman of Earth 42, it finally tracked its creators down to Earth 23, where it killed Jimmy and mortally wounded Clark. However, it found itself opposed by E-23's Superman, who with the help of Lex Luthor managed to temporarily strand it between universes before it could do any more harm.
Superdoom was ultimately summoned to Prime Earth by an unwitting Lex Luthor under Vyndktvx's direction as a final doomsday weapon against Superman alongside the other members of his Revenge Squad.
Superdoom at DC Database
Superdoom at Comic Vine