The Mirror Master is an alias used by super-villains to antagonize the super-hero, the Flash. Originally, assumed by criminal mastermind, Sam Scudder, and later by the Scottish assassin Evan McCulloch, the Mirror Master has been involved in various criminal activities, including his membership to the Injustice Gang, and the Secret Society of Super-Villains, marking him a great threat to the Justice League. He is a secondary player in the Non-Disney vs. DC Villains War.
The Mirror Master serves as one of the new additions of the malevolent organization, the Legion of Doom. He is summoned in Vandal Savage's estate, along with his fellow associates, to discuss about their next moves.