DC Universe Game Storyline
The opening cinematic takes place in a gritty, war-torn future depicting a final battle between the world's greatest heroes and villains. A future version of Lex Luthor provides voice-over narration.
This battle takes place in the ruins of Metropolis. Lex Luthor, wearing a heavy mech armor, commands an army of super-villains that includes Circe, Deathstroke, Black Adam, and Giganta. A scarred, armored Batman commands the heroes, which includes Cyborg, Flash, Green Lantern, and Wonder Woman. The battle culminates with the death of Wonder Woman at the hands of Lex Luthor, at which point an unshaven, weary Superman hears her dying screams from orbit and flies to Earth to confront Lex. As Superman cradles Wonder Woman's dead body, he collapses to the ground, and it is revealed that Lex hid kryptonite pellets in her mouth as a trap. Lex impales Superman with a kryptonite-tipped spear, and stands back to proclaim his victory, only to see Brainiac's war fleet fill the skies.
The scene then shifts to the present-day Watchtower where the future Lex Luthor, heavily modified with Brainiac technology, is telling the story to the present-day Superman, Batman, and Wonder Woman. Future Lex explains that the deadly final war between the heroes and villains was triggered by the subtle manipulations of Brainiac (who had been slowly downloading their powers over time). With the planet's most powerful beings dead, Brainiac intended to use the pirated data to create an army of metahumans under his control, facilitating his conquest of Earth. As the only survivor of the war, Lex Luthor could do nothing to resist Brainiac's subjugation of the planet. Lex Luthor explains that he was able to survive in secret and eventually seal the stolen data and energy from Brainiac's mothership in the form of "Exobytes" (nanobot-sized devices that can bond to a living host and give them their own superpowers). Lex has traveled into his past to release the exobytes into the atmosphere of present-day Earth. The heroes are outraged, but Lex Luthor explains that because he has done this, soon thousands of new metahumans will be created from ordinary humans (becoming the player-characters of the game). He implores the Justice League to find and train these new metahumans, because Brainiac is coming and the Earth must be ready to succeed where it was once doomed to fail.
When this cinematic ends, the player is brought to the character creation menu to build their new Hero or Villain.
In the second trailer to the game "In Lex we Trust", we find that Lex Luthor's description of events leading up to his arrival in the present time is not as he described to the heroes. The trailer begins with Lex Luthor reviving his companion Fracture from being unconscious. Lex Luthor explains that Brainiac's forces have already penetrated the Fortress of Solitude and that their time is running out. As they approach a time portal chamber, a Brainiac Eradicator attacks and Fracture destroys the robotic drone with a small grenade. The two arrive at the portal which is being stabilized by Batman (whose face is disfigured and arm is replaced by a robotic prosthetic due to injuries from the battle of villains and heroes). As more Eradicators enter the chamber, Lex Luthor lies saying his armor is damaged and that he can not hold them off. Batman tells Fracture to take the canister that contains millions of Exobytes and go through the portal attacking the Eradicators and buying him more time. Fracture thanks Lex for using the exobytes to give him his powers. Seeing the opportunity he had been waiting for, Lex Luthor kills Fracture describing him as "an excellent lab rat." As Lex Luthor is about to step into the portal, Batman calls to Lex Luthor warning that "I'll be coming for you" to which Lex responds "No, you won't" and activates a self-destruct sequence. Lex Luthor enters into the portal and the Fortress of Solitude suffers massive explosions. He arrives in a dark alley, presumably present day. He is greeted by his present-day self who describes him as being late.
It is then shown at the end of "The Prime Battleground" raid that Future Lex Luthor and Lex Luthor are working together to steal Brainiac's power. Lex Luthor is then betrayed by his future self as Future Lex Luthor wants the power for himself. It is then seen that Future Batman survived the explosion at the Fortress of Solitude and has been chasing Future Lex Luthor through time. Future Lex escapes and Future Batman follows him. In the following cutscene, Future Batman is said to be the last hope for humanity.
Following these events, the heroes are led by Future Batman while villains are led by Future Lex Luthor to the Nexus of Reality (the center of the Multiverse itself). Both sides fight for control, using paradoxes from constant time-travels to alter the histories of iconic characters, forcing heroes and villains to work parallel to each other, changing the timelines in the same fashion. What one causes, the other reverts, thus making an infinite cycle. This result in a massive paradox creature that consumes time itself. In the game's hardest raid, the player must stop the creature from destroying the time-space continuum (one of the many raids where both villains and heroes have the same goal). This event completely ends the storyline the game was based upon.
The DLCs provide new storylines to continue side missions (currently those about the Lantern Corps and the Amazons).