Pariah was one of the greatest scientists of his version of a parallel Earth. His unorthodox experiments to view the creation of the universe itself resulted in opening a portal to the Dawn of Time, where he viewed Pandora's Hand of Creation.
However, this intrusion, also opened a portal to the antimatter universe and freed the Anti-Monitor from imprisonment. Discovering Pariah's existence, the Anti-Monitor wiped out Pariah's entire universe, but it was only through the intervention of the Anti-Monitor's benevolent counterpart, the Monitor, that Pariah survived the assault. And as a result of what had happened, Pariah developed the ability to travel to one alternate earth after another, forced to witness untold millions perish as the Anti-Monitor destroyed one world after another. Eventually, he assisted the heroes of various alternate earths to destroy the Anti-Monitor and keep the resultant reformed single earth safe from harm. Pariah then joined Lady Quark and Harbinger in exploring the new earth, hopeful of what the future would bring.
Pariah later returned to warn the heroes of Earth of the coming war between the Roman and Olympian gods, which would destroy the earth if not prevented. Simultaneously, the Egyptian, African, Norse, Babylonian, and Thanagarian gods attempted to recreate the world in their own images. Eventually, the heroes won and saved their planet.
As INFINITE CRISIS approached, Pariah attempted to warn Lex Luthor of a dangerous predator, but this Luthor was actually the Alexander Luthor of Earth-3 in disguise and he murdered Pariah.
Pariah was later resurrected by the evil Dark Angel, but he fought against her and helped the Kryptonian super-heroine called Supergirl face her true self.
Because of the Crisis, Pariah's homeworld was retconned into being an alternate world from another dimension, rather than one of the infinite number of earths that had existed prior to the event. But this has changed now that the original multiverse has been restored during the events of CONVERGENCE.
In the current reality, Pariah was somehow caught and imprisoned by A.R.G.U.S., a U.S. federal agency that deals with interdimensional beings they deem threats to Earth. The circumstances of this capture remain unknown, but Pariah was able to escape due to the intervention of Justice League of America member, Vibe. His role in Rebirth has yet to be revealed, but rest assured he will be there to witness it all. It's possible he may currently be a prisoner of the enigmatic Mr. Oz.