The Rival (DC)

Clariss was a professor at the university attended by the Golden Age Flash, Jay Garrick. He believed he had recreated the formula that gave Garrick his speed.

Bitter at the rejection of his claims by the scientific community, Clariss became a criminal, wearing a darker version of the Flash's outfit. His version of the formula, however, proved to be temporary, and he was defeated when it was expended. He reappeared a few months later, and in battling the Flash, reached light speed and vanished.

JSA

Following the reformation of the Justice Society of America decades later, Clariss was retrieved from the Speed Force by Johnny Sorrow, who invited him to join the new Injustice Society. Now pure speed energy, he possessed Garrick's fellow Golden Age speedster Max Mercury.