Injustice 2

Plot

The story begins with Kara Zor-El running from Brainiac's army in her home of Argo City on Krypton. As Brainiac prepares to destroy the planet, she escapes with the help of her mother along with an infant Kal-El. Their pods head for Earth, but debris from Krypton's destruction knocks Kara's ship off course.

Years later, prior to the events of the first game and following Superman's murder of Joker, Batman and Robin attempt to stop the Regime from rounding up Arkham inmates for execution. Batman attempts to (literally) knock sense into Superman, but fails to dissuade him from continuing his extreme measures. Seeing Superman's new policy towards criminals aligns more with what he was taught by the League, Robin joins the Regime, killing Zsasz as a show of trust.

In the present, five years after the fall of the Regime, Batman and the Insurgency are attempting to rebuild society. However, a new faction, the Society, composed of villains spearheaded by Gorilla Grodd and his gorilla army, emerges and plans to gain global domination. With governments still rebuilding, and no military, Batman is forced to send his allies, Black Canary, Green Arrow from a parallel universe, and Harley Quinn to combat the Society in Gorilla City, where Doctor Fate warns Green Arrow and Black Canary of an incoming threat towards the planet. After defeating Grodd, the two are abducted by Brainiac, the true mastermind behind the Society. Having previously collected and destroyed Krypton, he had intended to reclaim Superman, but became interested in adding Earth to his collection. After Brainiac takes over Batman's communications hub, Brother Eye, Batman searches for allies to combat him.

Catwoman, Batman's double agent within the Society, frees Harley from Gorilla City. A pardoned Flash and a reformed Hal Jordan reunite before joining Batman, who sends the latter to Atlantis to gain Aquaman's assistance. Aquaman refuses to cooperate, but relents after Brainiac attacks Atlantis. Meanwhile, Black Adam, Wonder Woman, and Kara (having been rescued by Adam and taken the name Supergirl) attack the prison holding Superman, Nightwing and Cyborg, in order to free them and restore Superman's rule. Blue Beetle and Firestorm initially manage to hold off the Regime, but are eventually overpowered. Firestorm prepares to go nuclear as a last resort, but is stopped by Batman. Desperate to stop Brainiac, Batman releases Superman from custody and forms an uneasy alliance with the remnants of the Regime.

Cyborg, Catwoman, and Harley return to the Batcave to free Brother Eye from Brainiac's control and coordinate civilian evacuation efforts. Brainiac creates a pure machine copy of Cyborg called Grid to delay them. Wonder Woman takes Supergirl to Metropolis, and openly challenges Batman's plan. When she comes close to killing Cheetah and Harley Quinn, Supergirl stops her and heads to the Fortress of Solitude to confront Superman on the matter, learning the truth of her cousin's tyranny. With several cities abducted, Brainiac prepares to destroy Earth. The Insurgency and the Regime attempt to take on Brainiac's ship, but his shields are too strong and he apparently kills Superman in the process. They concoct a plan to weaken Brainiac's shields by using Aquaman's trident as a conduit for the magic of the Rock of Eternity.

Grodd pursues Aquaman and Black Adam with a brainwashed Black Canary, Green Arrow, and Blue Beetle. After Aquaman kills Grodd, the pair successfully weakens Brainiac's shields enough for Batman and Supergirl to break in. The two are captured, but Batman is rescued by Superman. After Superman and Batman defeat a brainwashed Firestorm and Swamp Thing, they are confronted by Doctor Fate, who is forced to help Brainiac by the Lords of Order. After defeating Doctor Fate, Superman destroys his helmet, removing the Lords' influence; however, Brainiac kills him. After incapacitating Brainiac, Superman takes control of the ship. He manages to restore most of Earth's cities, but loses New Metropolis and Coast City permanently, and the cities from other planets are still intact.

The heroes are divided over Brainiac's fate: Batman, Flash, Green Lantern, and Supergirl want to spare him in order to restore the rest of Earth's cities (as well as find planets for non-Earth cities to live on) and find a way to get New Metropolis & Coast City back; Superman, Aquaman, Black Adam, and Wonder Woman want to kill him to eliminate his potential threat and use his ship to restore the Regime's rule over Earth. After a brief argument, Batman attacks Superman with a gold kryptonite-laden dagger, and a battle ensues. The player must then choose between Batman and Superman, ultimately determining how the game ends. Batman and Superman defeat each other's teammates before engaging in a final battle against each other in the Batcave. If the player chooses Superman, he defeats Batman and the Insurgency, kills Brainiac, bonds with the ship, and forms a new legion consisting of the billions of Kryptonian, Daxamite, and Czarnian warriors trapped in Brainiac's collection in order to restore the Regime's rule. He offers an imprisoned Supergirl the chance to join his army, claiming he restored the remaining cities and put Earth at peace. When she refuses, Superman reveals, to her absolute horror, that he's used Brainiac's technology to turn Batman into a mindless slave, and then gives Supergirl two choices: join the Regime willingly, or Superman will do the same to her. The game ends before Supergirl's decision is revealed.

If the player chooses Batman, Superman is once again restrained by Batman and sent into the Phantom Zone as punishment. Superman claims he will return, with Batman acknowledging the likelihood of such an event and claiming he’ll be ready. He then tells Supergirl she is welcomed into his “circle of trust” and shakes her hand as the game ends.