Justice League

Green Lantern

In the 1993 Reign of the Supermen! storyline, the alien tyrant Mongul and his forces destroy Coast City (Jordan's former home), murdering all of its seven million inhabitants, and replace it with Engine City, with which he plans to turn Earth into a new Warworld. Jordan was off world at the time of the attack. Angered, he flies into Engine City and attacks Mongul, eventually knocking him out with Steel's hammer.[7] This leads into the Emerald Twilight three-part arc: Jordan uses his power ring to recreate Coast City as an instrument in the process of overcoming his grief, talking to ring created versions of his old girlfriend and parents. After his ring's power expires, a projection of a Guardian appears and admonishes him for using the ring for personal gain and summons him to Oa for disciplinary action.[8] Angered at what he sees as the Guardians' ungrateful and callous behavior, Jordan absorbs the energy from the Guardian's projection, goes insane and attacks Oa to seize the full power of the Central Battery, defeating and severely injuring several members of the Green Lantern Corps in the process, taking their power rings as his own and leaving them to die in space. He arrives on Oa and kills Kilowog, Sinestro, and all the Guardians except for Ganthet, who was protected by the other Guardians and survived without Jordan's knowledge.[9] He then renounces his life as Green Lantern, adopting the name Parallax after absorbing the Power Battery's vast powers.

Jordan is replaced by Kyle Rayner by Ganthet as the Green Lantern of Earth when Rayner comes into possession of the last power ring, created from the shattered remains of Jordan's. Guy Gardner has visions of the Green Lantern Corps' destruction and his yellow power ring's energy (being powered by residual Green Lantern's energy) starts to fluctuate. Soon after, Gardner goes to Oa to investigate. He brings Martian Manhunter, Darkstar (Ferrin Colos), The Ray, Wonder Woman, Captain Atom, Alan Scott and Arisia with him. Jordan uses the element of surprise, attacks, and quickly and easily defeats them, leaving Guy in a coma. After the battle Hal sends them all back to Earth warning them to leave him alone in the future. Not long afterwards, Parallax attempts to rewrite history to his own liking with the help of Extant in Zero Hour: Crisis in Time. Parallax destroys the Time Trapper and attempts to remake the universe into a perfect, peaceful place. The process causes time disruptions throughout time. Superman, Kyle Rayner and Metron call upon Earth's heroes to stop this crisis. Parallax reveals himself as the enemy by knocking out Superman with a single blow. Parallax and Exant battle the wide array of heroes. They are eventually defeated, with Green Arrow shooting an arrow into Jordan's chest after he is weakened and almost completely out of energy from using so much power to recreate time and fight Earth's heroes as Kyle Rayner holds him in a full-nelson. Later, in the 1996 Final Night miniseries/crossover storyline, Jordan returns when the Earth's sun is in danger of going out. He starts to reevaluate himself and the decisions he's made and attacks and kills the Cyborg Superman (although he is later revealed to be alive) and visits John Stewart in the hospital who was recently paralyzed in battle. Jordan talks to his old friend for a final time and uses his powers to heal his paralysis. He then uses what appears to be the last of his powers and sacrifices his life to reignite the Sun (which had been extinguished by the Sun-Eater).

During the Emerald Knights storyline, when Kyle Rayner goes on an accidental time-travelling trip, he ends up unintentionally drawing a past version of Hal into the present where Hal is shocked to learn of the crimes his future self had committed as Parallax.[10] Although Hal briefly thought about remaining in the present to escape his actions as Parallax, the Parallax from the time when he was starting the Zero Hour event appears in the present while preparing to recreate the universe. He had been travelling back to his present from the future and became aware of his younger self existing where he should not.[11] This Parallax from out of time tries to pass himself off as the young Hal, but after being discovered he defeats John Stewart, Guy Gardner and Kyle Rayner before being confronted by his younger self. Parallax pulls himself, his younger self and Kyle into the past where Coast City is seconds away from being destroyed and freezes time to show his younger self the atrocities of his hometown's destruction while also trying to explain why he did what he did as Parallax and that his ability to play god was necessary. After a heated battle and debate between the two Hals, Kyle breaks up the fight and tells them both that they have to go back where they came from and erase their memories of recent events in order to ensure that the Sun-Eater is defeated and that time plays itself out naturally.[12]