In the early years of the Great War, Guardian robots were used to quell uprisings in Cybertron's various city-states. They were colossal humanoid machines capable of unleashing incredible destruction, but even these mighty titans could not deter the Decepticons from their path of conquest. By the modern era, all Guardians on Cybertron had been destroyed, with only the Autobot Omega Supreme remaining.
Unlike Omega Supreme, the other Guardians did not have sparks and were not considered sentient. Their combat abilities are the same as Omega's, but Omega's spark grants him wisdom, insight and intuition, skills that have helped him survive the centuries of war that the other Guardians did not.