Liege Maximo

Evil is infinite, a natural counterforce to good in the universe that cannot be truly defeated. So when the first Primes were created, so was, necessarily, the Liege Maximo, the robot who now considers himself their opposite, the ultimate evil.

Pre-MUX continuity
According to the current Liege Maximo, Megatron and the Decepticons descended from the Liege Maximo line. The Liege Maximo's throne sits at the Hub, a network of planetoids created by the Cybertronian Empire that exists in the outer fringes of known space.

When the Cybertronian Empire started detecting radio signals from Earth, they sent a scout ship to investigate. Unfortunately for the scouts, the ship was boarded by Mecannibals and the crew killed and eaten, although not before sending a distress signal back to the Hub.

MUX History
The Cybertronian Empire scout ship continued its mission on autopilot, arriving in the Solar System and entering Earth's orbit, where it was found by the Transformers stationed there. After killing most of the Mecannibals, the Transformers discovered the ship was sent by someone called Liege Maximo, but currently don't know who or what that is.

Meanwhile, Liege Maximo has received the distress signal from the lost ship, and plans to send more...