Edward Clariss

Reverse-Flash is a name which has been used by several fictional supervillains in American comic books published by DC Comics. Each iteration is an enemy of the hero known as The Flash.

Edward Clariss (also known as the Rival and Rival Flash) first appeared in Flash Comics #104 (February 1949). Dr. Edward Clariss, a professor at the university attended by the Golden Age Flash, has recreated the formula which was behind Jay Garrick's speed as Velocity 9. He heard Joan Williams talking about how the Flash's own speed was given to another student, which helped him develop the formula. Bitter at the scientific community's rejection of his claims, Clariss becomes a criminal. A darker version of Flash with a mask over his head, he gives the formula to other criminals. The Rival's version of the formula is temporary, and he is captured and jailed.

JSA #16 (November 2000) contains a flashback to a battle between the Rival and the Flash several months after the former's first appearance. Now that he has inexplicably regained super speed, Clariss reaches light speed during the fight and vanishes into the Speed Force. After the Justice Society of America's reformation 50 years later, Johnny Sorrow retrieves Clariss from the Speed Force and invites him to join the Injustice Society. Driven insane in the Speed Force, The Rival races across the country on a killing spree. The Flash realizes that the Rival's path across the country spells out Clariss' name and the final murder will be Joan; Jay absorbs the Rival's speed before he can kill Joan.

The Rival returns in Impulse #88 (September 2002), posing as Joan's doctor. Now pure speed energy, he possesses fellow Golden Age speedster Max Mercury. After battling Jay and Impulse, Max time-travels to an unknown destination. In The Flash: Rebirth #4, Max escapes from the Speed Force and is rejuvenated by Wally West's energy; this allows him to return to Earth in a new body. Another Golden Age Reverse-Flash is a robot whose only appearance was in one panel of The Flash vol. 2, #134 (February 1998), where he is defeated by Garrick.

...
Wikipedia