The Fastest Men Alive of five Earths faced several ferocious foes, but perhaps none as tenacious as these masters of mirrors. Unlike their peers, these rogues had the means to succeed, given their tremendous creative minds. Three of these were criminals who discovered terrorizing technology, while a forth was a hero and the fifth was a bounty hunter!
Scudder's Mirror Master identity on Earth-One's caused Central City terror throughout the years during various clashes with his scarlet-clad opponent, Whether using reflective weaponry, traveling to the fourth dimension via a mirror, granting himself superhuman power or altering his adversaries personalities into a dark reflction of himself... Sam never ran out of tricks to terrorize. He would be instrumental in forming the Rogues Gallery that plagued Flash aka Barry Allen, consisting of several arch enemies of the hero. He would also eventually join such teams as the Injustice Gang and Secret Society of Super-Villains.
Schudder's Earth-Two counterpart was optometrist Jonathan Cheval, who followed his father's trade and built up a business for himself. When corrupt bankers stole from Cheval's payments on his business location to cover their financial losses, this left Jonathan destitute. Seeking revenge, Cheval as the Monocle...of Mister Monocle as the Flash would later call him... incorporated his technological advantages in harnessing lasers and cosmic radiation into his eye pieces. Hunting each of the bankers, the Monocle's vengeful path was stymied by the intervention of Hawkman. Soon after, Monocle recruited a gang of hoodlums and employed even more methodical schemes in a crime wave he started in Keystone City. This caused him to face his world's Flash, whom he exposed to other gadgetry he had devised such as various mirrors and images projected as well as vicious hand held implements of death. Once more, he was defeated... and decades later as a seemingly reformed inventor in France, Chaval was enticed once more into criminal endeavors by the Ultra-Humanite. Joining the Secret Society of Super-Villains, Monocle once more faced his two arch enemies in Hawkman and the Flash.
Then there was the Mirror Master of Earth-148 whom the Earth-One version stumbled upon while using one of his devices, thinking he was as evil as him when he witnessed Samuel-148 defeating that world's Flash. In reality, Scudder there was a hero and Flash a villain, and so the device that Samuel-One used was ineffective on his dimensions Scarlet Speedster. A final Mirror Master would reveal himself in battle versus the Flash of Earth-D aka Tanaka Rei, whom Barry witnesses battling just prior to the Crisis on Infinite Earths wiping out that reality. Each of these Masters of Mirrors working on both sides of the law, whether solo or alongside their fellows, were consistent in their propensity to torment their worlds' respective Flash.
The Earth-Three Mirror Master was one of five core members of the superhuman bounty hunter team known as the Rogue Hunters. Allied alongside that world's version of the Top, Captain Cold, Weather Wizard and a female Captain Boomerang, the quintet gained notoriety at their long running enmity with the arch antagonists of humanity in their reality, the Crime Syndicate of America, and its fastest member Johnny Quick. In fact, their last chronicled case was on the world during the Convergence event when the Hunters battled the powerless Syndicate and yet faced defeat as they had done in the past.