Megatron (Tyran)/208.28 Gamma

Megatron is a character from the Transformers comics.

History
The All Spark had not been blindly launched into space, however - its trajectory was leading it directly towards the Alkaris Anomaly, a wormhole that could potentially transport the cube to any one of an infinite number of locations in the universe. Megatron was fully capable of catching up to the cube before it would enter the wormhole, but as he passed Cybertron's moon, he found himself ensnared by an Autobot tractor beam of remarkable strength that pulled him down to the moon's surface. Enraged by the ignominy of it all, Megatron turned his weapons on the Autobots responsible, but quickly calmed down enough to realize that this was only playing into their hands, and instead ordered Brawl to take his place in the battle. Megatron swooped back into space, hot on the All Spark's heels, but was unable to stop the cube from falling through the anomaly. Determined to have the All Spark's power, Megatron chose to enter the wormhole himself, only to be spat out in some far-off star system, with no trace of the All Spark.

In another reality, he defeated Optimus at Mission City, killed Sam Witwicky and took control of the All Spark. He was fully linked to it and drew on its power - "It is me and I am it!" - giving him greater might and the ability to heal any wound.

After conquering an unknown chunk of Earth (including the entire United States of America) with Dropkick as his second-in-command, he used the All Spark's power to start turning Earth from an organic world into a new Cybertron. Optimus Prime lay frozen in the old Sector Seven base, Autobot resistance was scattered, and NATO's threat to use nuclear weapons on occupied America was hardly much of one. The only thing bothering Megatron was those rebels breaking into Hoover Dam... Megatron personally arrived to face Bumblebee and hunted for him, trying to bait him into appearing.

Realizing the Autobot must have come with a human ally, he deliberately threatened to go after the human and thus got an emotional Bumblebee to make a defiant attack... at which point he backhanded Bumblebee into the wall and prepared to eviscerate him. He gave the Autobot a chance at a swift death if he begged for mercy, and was quite impressed when Bumblebee merely asked "that all you got?", but was less impressed when Autobot reinforcements, about 111, arrived. He effortlessly smashed them aside and was about to kill Skyblast when a new challenger arrived: the revived Optimus!

Optimus Prime got the snot beaten out of him, every attack he landed on Megatron being repaired by All Spark power. However, he distracted Megatron long enough for Bumblebee to hit him with the other thing they'd broken into the Dam for: Sector Seven's greatest weapon, a nanovirus that targeted All Spark operation frequencies. Infected, the tyrant was consumed from within by his own power and collapsed dead.