Mirage is a former member of the Knights of the Ashen Flame who originally served as a member of Special Fire Force Company 3, where he operated as a spy alongside another agent known as Flail. He appears as a secondary antagonist primarily during the Vulcan's Workshop arc and the Netherworld arc. His background is tied to the White-Clad's infiltration of the Fire Force, and his actions serve the group's larger agenda.

Mirage's personality is characterized by his deceptive and tactical nature. He uses his abilities to sow confusion and evade direct confrontation, preferring to rely on his illusions rather than face opponents head-on. His motivations align with the White-Clad's goals, though his personal reasons for joining the cult are not deeply explored. In the story, he plays a role in the assault on Vulcan's workshop, aiding Flail in attempting to eliminate the workshop's protectors. He later participates in the conflicts within the Netherworld.

His key relationship is with Flail, with whom he works closely as a team during missions. He opposes the members of Special Fire Force Company 8, particularly Arthur Boyle, who easily destroys his clones with his plasma sword Excalibur. Mirage's development is minimal; he remains a relatively static antagonist who reappears in later arcs without significant personal growth.

His notable ability is generating heat haze mirages that create convincing illusions of himself. He can produce a small army of these mirages to confuse enemies, avoid direct hits, and set up ambushes. However, his illusions are not invincible—they can be overcome by sufficient perception, special equipment, or abilities that cut through deception, as demonstrated when Arthur's sword dispels all his clones at once.