Injustice Story Mode - The Flash

In the altered reality, the Flash appears as a member of Superman's One Earth Regime. He and their universe's Shazam venture to Atlantis to meet with their Aquaman and finalize the treaty he agreed to sign, unaware that the Aquaman that they meet with is actually the displaced Aquaman from the other dimension. Upon reading the treaty and finding out that it entails Superman's complete takeover of Atlantis, Aquaman refuses to sign it, prompting a fight between him and the Flash, which Aquaman wins.

Back in their dimension, the Flash and Cyborg devise a plan to pull their allies back into their dimension using the Flash's Cosmic Treadmill. They make the neccesary modifications and put their plan into action. However, the inter-dimensional gateway belonging to the Insurgents activates at the same time, pulling Cyborg into their dimension.

The alternate Flash later appears in the Watchtower alongside Shazam. Both of them begin to question whether or not they're still doing the right thing in following Superman's Regime. Just then, they're confronted by Deathstroke , who knocks them both into the reactor room using motion sensor bombs. The Flash clashes with Deathstroke but is beaten, followed by Shazam. He and Shazam are teleported off of the Watchtower by the displaced Cyborg before it explodes.

After the attack on Stryker's Island, the Flash and Shazam appear at Superman's council meeting, where he announces his intention to destroy Metropolis and Gotham to set an example to the people, then invades the duplicates' universe for interfering. When Shazam challenges Superman's decision, he promptly kills him by using his heat vision to burn through his eyes all the way through the skull, thus confirming the Flash's belief that they are no longer doing the right thing. The Flash defects from the Regime, subduing Yellow Lantern and Solomon Grundy when they attempt to stop him from leaving. Using the coordinates given to him by Killer Frost , the Flash rushes to warn the Insurgents of Superman's plan. He briefly detours upon seeing Sinestro about to execute several renegade soldiers before the entire army. The Flash quickly disarms all of the soldiers and confronts Sinestro, who promptly launches him into the air. He lands in front of Wayne Manor, where he and Sinestro face off. Once he has him beat, the Flash builds a pyramid of stone bricks around him so he won't escape. He then proceeds to the Insurgency, where he is surprised to encounter the displaced Green Arrow, who he believed to be dead. Seeing him as a threat, Green Arrow attacks the Flash, but they both manage to come to an understanding.

The Flash explains Superman's plan to the Insurgents and helps defend their base when they are attacked by the Regime. When the battle is moved to the streets of Gotham, he fights Yellow Lantern by running circles around him, only to be knocked back by the Lantern's shockwave attack.

In the epilogue, the Flash willingly turns himself in due to his previous allegiance with Superman's Regime to answer for his crimes and atone for his sins. He manages to give Green Arrow one last smile before he is taken away.