Cybertron

Cybertron is the homeworld of the Transformers, the body of their Creator Primus, and the source from which all Energon (minus Dark Energon) originates. The planet was (apparently) once lifeless until the Creators came and cyberformed the planet, creating the race of Transformers. Some of the most known Cybertronians who inhabited Cybertron were the Autobots and Decepticons. Notable Cybertronians who led the planet's inhabitants were Optimus Prime (known back then as Orion Pax) and Lord High Protector, Megatron. Eventually, War erupted on Cybertron between the Autobots and Decepticons, for control of the planet and its energy resources. The Autobots fought to save the planet while the Decepticons sought to conquer it.

Eventually, the War depleted most of Cybertron's energy reserves and the Core itself was poisoned. This forced both the Autobots and Decepticons to evacuate the planet, which ultimately brought them to the distant planet Earth. Shockwave was initially put in charge of the planet after the Decepticons left in pursuit of the Autobots, but the Scientist eventually travelled to Earth himself, leaving the planet leaderless. This enabled the space sorceress Quintessa and her Infernocons to seize control. Splitting the planet apart, Quintessa guided Cybertron toward Earth, intending to revive the planet using the life force from Earth (in reality Unicron). After the Autobots stormed Cybertron and vanquished Quintessa, the planet was placed back under Autobot control and partially connected to Earth. Following Quintessa's failed plan, Cybertron had regained enough energy to once again sustain life. Galvatron and Cyclonus would call a truce with the Autobots, making sure to begin his plan for the destruction of all Cybertronians.

5 years later - Galvatron would once again plot to defeat the Cybertronians, after gaining warriors from the past, present, and future. He would begin to host gladiatorial combat and would begin to restore Megatronus Prime and Quintessa. Cyclonus would eventually find an ancient threat, one that was far more powerful than Moltenstorm and Quintessa, one that could be shaped by Galvatron into a powerful ally. The Cybertronian was hidden in a tomb deep below Cybertron, a tomb filled with the remains of thousands of bodies. The unknown ancient being would be christained as Nemesis Prime - a dark threat that looks and sounds like Optimus, but is black and gold.