Unicron

Bio
Unicron is the true main antagonist of Transformers: Prime. Before the dawn of time, he is known as the bringer of chaos, lord of the undead and one of the main sources of evil in the entire universe and the very source of Dark Energon itself. As an immortal and eternal being with immense power, Unicron is the polar opposite and eternal arch-enemy of his twin brother, Primus, the creator of the Transformer race. During the battle between Unicron and his brother at the beginning of time, Unicron was cast out by Primus and the Thirteen and over time matter formed around his body and he became the planet Earth itself, which he became the creator of humankind. In his time of absence, Unicron would be the source of myth, legend and fear across all of Cybertron and the universe.

Unicron would be dormant for billions of years until the planetary alignment that would reawaken him leading to a temporary team up between Autobot and Decepticon to defeat him, rendering his physical form dormant, seemingly trapping him within the Earth's core for good. This would not be the end for him, however, as a few years later, Unicron's energy form would be reawakened after the restoration of Primus/Cybertron. His physical form useless, his anti-spark was forced to revive Megatron and use him as a vessel and headed to Cybertron to destroy his arch rival. Unicron would use an undead army of Predacons to accomplish this goal forcing the Autobots once again to fight against him, this time with the Predacons. Thanks to Optimus Prime Unicron was sealed within the AllSpark container, which trapped his Anti-spark for good.

However, thanks to Galvatron for reviving his master, Unicron has return for the third time.