Rise of the Twilight Empire
Cog is a warforged whose fate is inextricably interwoven with the fate of the world. There has been a prophecy that he will be present at the last battle for reality. Built during the waning days of Nerath by the royal family, he slew many beastmen before falling in battle to Yeenoghu’s horde. He was eventually repaired, though gaps in his memory remained.
For a time he joined the Devil’s Teeth mercenary band, and was instrumental in the fall of Thoren Brighthammer. He eventually left the service of that famed group (or was he expelled? His memory is not what it once was…) and joined with the current group in their quest to defeat Vecna and discover why the Throne of Heaven is empty.