Gherak is a Deathwatch Black Shield, who serves the Inquisitor Lord Otto Dagover and is also secretly a surviving member of the destroyed Flame Falcons Chapter.
Exactly how Gherak survived his Chapter's purge at the Inquisition's hands or came into Dagover's service, is unknown. He has, though, carried out several missions for the Inquisitor Lord, including being a member of a Kill-Team sent to Discidia. There they were charged with recovering a weapon of the Cyranax Watchers, which had been uncovered in a dig site within Discidia's Vorago Fastness prison complex. Inquisitor Armand Salmenau had been overseeing the dig site, but the Necron had unexpectedly attacked his retinue after the Cyranax weapon had been discovered. The Xenos attempted to claim the weapon from the Inquisitor and an ill-prepared Salmenau was forced to seal the entrance to the dig site. In Dagover's mind, however, the Cyranax weapon belonged to him and the Kill-Team was to ensure that neither Salmenau or the Necron possessed it. Once the Kill-Team reached the Vorago Fastness, they fought their way through the attacking Necron, though the Xenos managed to heavily wound the Flesh Tearer Utor. His wounds nearly caused Utor to fall to his Chapter's curses, but Gherak reached his side and implored the Flesh Tearer to draw strength from the Emperor's light. Gherak then stated that the Kill-Team needed Utor's aid if they were to succeed and the Flame Falcon's words brought the Flesh Tearer back from the abyss he was approaching. Once he recovered, Utor was extremely grateful for Gherak's help and was able to continue the mission. The Kill-Team later reached Inquisitor Salenau's position, but he pleaded with them to not take the Cyranax weapon. The Inquisitor warned them that if they did, Dagover's Radicalism would ensure the Kill-Team went down a path that led to Heresy against the Imperium. Salmenau then asked them to disobey Dagover's orders, but the Kill-Team refused and the Inquisitor said they would have to kill him to take the weapon then. Seconds later, though, a Necron Lord led another attack on the dig site, whose doors had remained opened after the Kill-Team had entered. The now damaged doors could not close and in the ensuing battle, Gherak's Gene-seed mutation activated and his body was covered in flames that burned the Necron. This was not enough to defeat the Xenos, however and the Kill-Team was forced to fire the Cyranax weapon to save themselves. The resulting fire not only destroyed the Necron, but also carved a path of destruction across Discidia's surface. The entire Kill-Team survived the mission, though, and they returned to Inquisitor Lord Dagover with the Cyranax weapon.