The Flame of Azeroth is a sacred treasure of the Halcyon Knights.
When Coop accidentally destroyed the Flame of Azeroth, their sacred treasure, the emperor issued a challenge to the robots who were competing to claim his throne: bring him the robot who destroyed the flame to face judgement. When Zanzaor brought Megas back he was named emperor. He tried to execute Megas for destroying the flame, but Coop broke free and destroyed Zanzoar. Then suddenly, Coop activated Megas' flame hands. This function led the knights to believe that he was part of a fabled legend and Megas re-ignited the sacred Flame in gratitude, but it started burning everything in its path. Coop decided to escape and fled just before Halcyon blew up, with the Flame of Azeroth with it.