Jonah Hex was an outlaw, and later a bounty hunter in the late 1800s. He was easily identified by the right side of his face being grotesquely scarred, which hides his honorable nature.
As a Bounty Hunter
Hex pursued Duvall to Ra's al Ghul's airship The Phoenix, where they faced off. Hex took on the saber-wielding Duvall with only a bowie knife. Midway though the furious duel, Hex caused the ship to lose altitude and it caught fire. Ra's escaped the ship in a personal glider, leaving Duvall behind.
The ship crashed, throwing both Hex and Duvall free. Amidst the debris, Duvall begged for his life, but Hex told him he had no interest in killing him if only because it is more convenient to deliver him alive to the law. After he finds his hat that he lost earlier, Hex remarked ruefully, "I'm gettin' too old for this".
In 1879, Hex teamed up with Bat Lash, El Diablo, and Ohiyesa Smith, and later also Batman, Wonder Woman and John Stewart, to overthrow Tobias Manning's control over the town of Elkhorn. Here it's revealed that Hex had some time travel experience. He recognized the Justice Leaguers as time travelers and had developed a negative opinion of "ray guns".