Gazer met the X-Men when a massive Golgotha invasion threatened Earth. He was permanently stationed alone on NASA Space Station Eight, because due to his mutant abilities, he was the only person to withstand the high levels of radiation. Upon detecting the impending psychic alien creatures, he alerted Emma Frost of their approach. The X-Men soon joined him on his observation platform as a staging post for battling the Golgotha.
Following the events of House of M|"M-Day,", Gazer was one of the many mutants who lost their abilities. He soon contracted radiation sickness. After losing sanity and hope, Gazer jumped out of the station in his space suit, claiming if he's going to die, he's going to die "out there." Just as soon as he made peace with his death, a blinding light appeared and he found himself before Apocalypse.
Apocalypse thrust him into a battle to the death with an egyptologist for the honor of becoming his Horseman, War. Gazer was overpowered, and before he was dealt the final blow, Ozymandias saved him and told him he would one day repay the debt, as the scribe was planning to overthrow Apocalypse. During Gazer's transformation, Apocalypse denied him painkillers, stating that the pain was a part of the process of becoming War. After it was complete, Sunfire tried to free him and escape, but it was too late. Gazer was gone, and in his place there was War, a loyal Horseman.
While Apocalypse was recruiting the 198, a band of mutant refugees outside the Xavier Institute, War demolished the unmanned Sentinels standing guard. Ozymandias soon grew tired of Apocalypse's plans and approached War to aid him and repay his debt. However, the loyal Horseman relayed the scribe's traitorous plans to his master. The X-Men had Sunfire in their custody, who was now the Horseman, Famine. War broke into the mansion to retrieve him, was met with significant resistance, and forced to retreat.
With Apocalypse's Sphinx threatening the United Nations, and the Avengers and the X-Men storming the ship, War stayed at his master's side. However, Ozymandias snuck up behind him and ran a battle axe through his chest for denying him his repayment.