Who is The Rival? DC's FIRST Reverse-Flash Explained
In comics, a hero is only as good as his enemies. And while The Flash has one of the most iconic and diverse rogues galleries in the DC universe, his true nemesis has always been the Reverse-Flash. But long before Barry Allen became The Flash and was fighting Eobard Thawne, Reverse-Flash of the future, the Jay Garrick had his own 'Reverse-Flash' to battle. His name was Edward Clariss... but he called himself The Rival, sworn enemy of the Golden Age Flash.
Created by John Broome and Joe Kubert for Flash Comics #104 (1949), Edward Clariss was a professor at Midwestern University where Jay Garrick attended as a student. When Jay accidentally gained his superhuman speed and reflexes by inhaling heavy water vapors during an experiment, he used his powers to become The Flash. When Clariss overheard Jay's girlfriend Joan Williams tell another student about Jay's secret, he recovered the only surviving sample from the accident and sought to recreate the speed-granting formula. When his results were mocked and dismissed by the scientific community, Clariss used his special formula to give a group of hired criminals super speed. And soon, gave himself the upgrade, as well.
Dressed in a similar outfit as Jay Garrick but wearing a mask, Clariss called himself the Rival and used his powers to go on a crime spree while attempting to take away Jay Garrick's powers for good. Jay was eventually triumphant and defeated Rival whose identity and backstory was eventually revealed. The powers granted by his formula proved only to be effective in short periods and the former Rival didn't even remember Jay's other identity upon being arrested.
A few decades later, his absence was explained in JSA #16 (2000) by Geoff Johns, David S. Goyer, Stephen Sadowski, and others in a flashback taking place a few months after his first appearance. Revised to no longer an old man, the Rival broke out of prison and had The Flash hot on his heels but with the unexplained return of his super speed, Clariss managed to accelerate to the point of lightspeed and disappeared into the Speed Force.
He would remain in the Speed Force until the villainous Johnny Sorrow freed him and asked him to join the modern day Injustice Society, enemies of the Justice Society of America whom Jay Garrick was a founding (and current) member. Driven insane by his imprisonment, Clariss got the JSA's attention by murdering people in various places simply so the locations would spell out his name and then targeted Jay's wife Joan in order to draw his old nemesis out. When Jay is able to match Rival's speed, he realized that Clariss had become nothing but Speed Force energy during his exile and in order to stop him, he absorbed part of that energy which left him victorious despite an odd temporary side effect.
The Rival wouldn't make an appearance until Impulse #88 (2002) when he reappeared posing as Joan Garrick's doctor as she underwent cancer treatment. Once his ruse was uncovered in the story by Todd Dezago, Carlo Barberi, and Terry Austin, a furious Jay and Rival battled, almost culminated in Jay killing Clariss if not for the intervention of Impulse.
Eventually Rival revealed that he was simply a distraction in a much bigger game and that The Flash's enemies who freed him allowed him the ability to possess another speedster's body, Bart Allen's former guardian and mentor Max Mercury who had been missing. Unable to kill Clariss due to the fact that it would doom Max to be imprisoned in the Speed Force forever, Clariss disappeared in Bart Allen's time capsule with Max's body to an unknown period in time.
Edward Clariss has not been seen since then although Max Mercury has reappeared in both Infinite Crisis and was brought back to life by Barry Allen during the Flash: Rebirth series. Whether or not he still occupies Max Mercury's original body, Edward Clariss has proven that he is truly Jay Garrick's Reverse-Flash, committed to using his powers and hate to destroy everything in Jay Garrick's life.
Although he appears to be gone, the Reverse-Flash has cheated death before and with Jay Garrick returning to DC Comics, so it's only a matter of time until the The Rival returns to fight once again.