The Firstforged Maximo was the third Cybertronian to demerge from Cybertron. He is believed to have demerged in Kaon. Maximo was the warmaster and general of the Firstforged, the 'burning hand of Primus' and leader of warriors in battle, and perhaps the greatest in terms of sheer power. His spawnlings were known as the Maximals and his line of descent as the Legira ["the bequeathed"], later the Legascions ["inheritors of the bequest"].

Primordialists believe Maximo created to guard Cybertron from alien invasion, explaining why he was created so long before the awakening of the demons. He is considered the inventor of military tactics and strategy, the organization of armies and the principles of warfare. He was present at the death of Armada, and the death of his brother - one way or another - caused Maximo and Prima to have a permanent parting of opinions. The death of Armada also placed upon Maximo and all his descendants the Liegeline curse, causing any of Maximo's line to feel the death-agonies of their progenitors, spawnsibs and spawnlings.

After the fall of Prima, Maximo sought to overthrow Prime Nova and take contol of Cybertron, but was betrayed by Decipatron. He was either defeated by the Second Generation and exiled, or simply left Cybertron in disgust. Most Primordialists and Deciprimordialists believe Maximo lives somewhere in the far reachs of space, reigning over a great empire of Cybertronians created from his own being. The Overlords considered themselves to have the purest Maximo programming, and themselves to therefore be his inheritors and descendants.

The name "Maximo", meaning "strongest principle", is a translation of the meaning of his name in Ancient Cybertronian. In Primaltongue he was called Jwachyaronos meaning "I am the greatest acting thought". In Modern Autobot he is called Miueichon meaning "the greatest principle, our respected opponent". Miueichon is transliterated into Murion as Miaw Eoman. In High Legion he was called A'tesu-ohu-sa'ase-suo, roughly meaning "grand silken-steel thought in action", a metaphor that defines the majesty of Maximo's thoughts as being like the movement of molten steel. Maximo is so linked to the Legascions that he is usually, like their leaders, referred to with the Liege title - i.e. Liege Maximo. In Modern Decepticon he is called Vashaklaron, meaning "the strongest thought, who left".