The crossover began in January 2011 in the Steel one-shot published as part of the DC Icons line. The crossover continued in Outsiders #37, where Doomsday faced Eradicator, Justice League of America #55 and Superman/Batman Annual #5, both of which involved him facing Supergirl and Cyborg Superman, Superboy #6, where he faced Superboy, and Action Comics #900-904, where he faced Superman. The storyline concluded in #904, the final issue of the first volume of Action Comics preceding the title's relaunch as part of The New 52.
Plot synopsis
When Doomsday lands in Metropolis, Steel fights the creature and loses. Doomsday takes Steel and departs from the scene. Doomsday then attacks the Outsiders in Markovia, intent on finding Eradicator. After defeating Eradicator and his teammates, Doomsday flees the battlefield with his body. Doomsday later attacks the Alpha LanternBoodikka and several members of the Justice League. The Cyborg Superman emerges from Boodikka's body and reveals that Doomsday has come for him. Cyborg Superman wounds Doomsday, who then assimilates Cyborg Superman's nanotechnology and rebuilds himself into Cyborg Doomsday. Supergirl arrives and aids Cyborg Superman against Doomsday, but Doomsday overpowers them both and teleports away with their bodies. Doomsday subsequently attacks Superboy. Superboy is overwhelmed, and Doomsday teleports to a large alien spacecraft on the ruins of New Krypton. Superman discovers this was all part of a plot by Lex Luthor to distract him from Luthor's ultimate goal of finding a Black Lanternpower ring. With Luthor defeated, Superman finds his allies trapped in a pocket dimension within a satellite. Superman attempts to free his allies, only for them to discover the inert body of Doomsday, as well as three separate clones - each with a different powerset designed to specifically make them capable of eliminating the Superman they were sent after. Superman and his allies escape, taking the original Doomsday with them. Steel notices Doomsday is beginning to regain his brain activity when they are attacked by the Doomsday clones. The heroes are met by another Doomsday clone, Doomslayer. The Eradicator, against Superman's suggestion, fights the Doomslayer and is destroyed. Doomslayer intends to crash the ship into Earth and attacks Doomsday. Superman defends Doomsday, believing Doomsday has the potential for redemption. The heroes escape the ship with the original Doomsday. Superman and his allies try to stop the ship from crashing, but are not strong enough. Superman advises Superboy, Supergirl and Steel to escape while he slows the ship down, intending to sacrifice himself. The ship falls in Metropolis's bay and creates a massive tidal wave. However, Superboy's tactile-telekinesis, Supergirl's cold breath and Steel's gravitron source dissipate the tidal wave, saving Metropolis. As Superman crawls out of the sea, Doomslayer attacks the city with the four Doomsday clones. The Doomsday clones spread across the world, wreaking havoc. Doomsday awakens, but the Eradicator speaks through him. The Eradicator, as a being of pure information, leapt into the technology Luthor used to clone Doomsday so that he could control the original Doomsday. As the heroes fight the Doomsday clones, Eradicator begins to feel Doomsday's mind regaining control of the body. The Eradicator sacrifices himself to send Doomslayer and the other clones to a different dimension.
Titles
In addition to the Steel one-shot, the crossover includes issues of Justice League of America, Outsiders, Superman/Batman, Superboy and Action Comics.
Part 1: Steel #1
Part 2: Outsiders #37
Part 3: Justice League of America #55
Part 4: Superman/Batman Annual #5
Part 5: Superboy #6
Part 6: Action Comics #900 - This issue is also the conclusion to Lex Luthor's The Black Ring storyline
Beginning with part 7, the storyline was retitled The Reign of the Doomsdays
Part 7: Action Comics #901
Part 8: Action Comics #902
Part 9: Action Comics #903
Part 10: Action Comics #904 - Conclusion and final issue of Action Comics volume 1.