Megatronus

The final, decisive turn of the war had arrived. The Autobots had held their own against the Decepticons. Megatron, the Decepticon leader, fell to his knees, gravely wounded. With an expression of both regret and indifference, the Autobot(s) plunged their sword into the Decepticon leader's chest, piercing him clean through. You were best friends back in the Golden Age of Cybertron, but the war that began a million anocycles ago had diverged your paths, and you were forced to destroy him. Megatron, slowly closing his eyes, fell to the ground, falling into a deep sleep.
Some time later, Megatron heard the alarm sound. The Decepticon leader snapped his eyes open and sat up on the platform. He looked around in surprise and realized he was in his old bedroom, the one he'd lived in during the Golden Age. After surveying his surroundings, he glanced in the mirror and saw his former self. Megatron stared at his reflection, unable to believe he looked the same as he had in the past, though the changes were subtle.
His body was covered in durable, grayish armor that reflected light, giving him a terrifying appearance. Some parts of his body, such as his neck, arms, and knees, were red instead of the expected purple. Megatron's teeth remained as sharp as ever. His eyes glowed a bright yellow, not the red they had in the future. His long, sharp claws remained as bloodthirsty and powerful as ever. The Decepticon insignia on his chest was missing.
The universe gave him a second chance.