Unicron

Origins
Unicron's existence dates back to the beginning of time. When the previous universe ended with its Big Crunch, Unicron was a member of what would be considered a godlike species. After the big bang, Primus and Unicron were the only survivors of their kind. While Unicron was filled with hatred, Primus was filled with hope. Their viewpoints caused an intergalactic war which resulted in Primus laying dormant for millions of years as a planet and Unicron being sent to the fourth dimension.

Return
After thousands of years, Unicron returned in the Andromeda galaxy. It would not be known for another few years that his presence in the other dimension led to the "higher powers" knowing of our existence. They blessed Unicron with great power so that he could destroy Primus forever. However, he waited patiently for the right moment.

The Great War
Towards the end of the Great War, Unicron communicated with the Decepticon Fear telepathically, telling him to revive him so he could destroy Primus. Fear not only did so, he also summoned a Unicron from another reality. One of them was teleported to another place in the Universe by an artificially created black hole, and the other was destroyed from the inside by electromagnetic energy.

Current Whereabouts
The Unicron that was defeated by the black hole ended up in the Alpha Centauri system, once again waiting patiently for the right moment.

Weakness


Unicron's one true weakness is the Autobot Matrix of Leadership, a device created by Primus and passed down to the great Autobot heroes on Cybertron. It's currently resting in a secure facility near the city Tricon.