Gazer was a mutant with the power to metabolize large doses of radiation. Prior to M-Day, Gazer worked alone on a space station observing the solar system. After losing his mutant powers on M-Day, Gazer was unable to continue surviving his exposure and accepted his grim fate. Before this could happen he was rescued by Apocalypse to be a part of his new team of Horsemen of Apocalypse.
In Apocalypse's temple, Gazer was told that he would have to fight to the death for the right to become one of Apocalypse's horseman. Ozymandias rescued Gazer by slaying his would-be killer so that Gazer would owe him a favor as War. Gazer's transformation into War was long and painful. In the process his physical size and mass was increased, and his facial features were enlarged. During the changes Sunfire could hear Gazer's screams and tried to rescue him. It was too late, however, because by the time Sunfire got to Gazer, he had been fully brainwashed and genetically altered into Apocalyse's third horseman, War.
He was soon revealed to the X-Men. Shortly after landing his temple at the Mansion Grounds, Apocalypse released war to combat the X-Men and the Sentinel Squad. War's immense strength coupled with the powerful concussive blasts generated by his mace made him a force to be reckoned with, even for the new Sentinels. Gazer's tenure as War was short lived as he was slain by Ozymandias in Apocalypse's presence when he refused to turn on his master.
Gazer's mutant power was to absorb and metabolize lethal amounts of radiation for sustenance. Physically gazer has grey skin and several unique facial features (particularly his large eyes and small brow).
As war Gazer's physique was enlarged by Apocalypse, and his strength and durability were increased to superhuman levels. Although he lost his original mutant powers on M-Day, he was also given the ability to absorb solar energy and convert it into powerful optic blasts. As is the case with many of Apocalypse's non-flying horseman, Gazer was given a large mechanical horse for flight. He also carried a large mace capable of generating concussive electrical blasts.