Megatron - (TFP)

He began as an unnamed miner, identifiable only by his designation (D-16). Upon becoming a gladiator in the arenas of Kaon, he adopted the name Megatronus and led a political movement against Cybertron's rigid caste system. During this time, he forged a close friendship with a young archivist named Orion Pax. He presented his ideas to the High Council, demanding the overthrow of the system by force. When the Council favored Orion Pax's peaceful stance and appointed him Optimus Prime, Megatron felt betrayed. Filled with resentment, he severed ties with Orion, founded the Decepticons, and initiated the devastating civil war that rendered Cybertron uninhabitable. After eons of wandering the cosmos, he arrived on Earth carrying Dark Energon (the blood of Unicron). His obsession with infusing this substance into his own body led him to experience visions, mental instability, and a symbiotic connection with the God of Destruction, losing sight of his original purpose and ruling solely through terror. During the final battle aboard the Nemesis, Megatron was impaled and killed by Bumblebee using the Starblade, his body falling to Earth. Some time later, Unicron took possession of his corpse, reanimating him to destroy Primus and the restored core of Cybertron. After being freed from Unicron's mind control by Optimus Prime, Megatron experienced for the first time what it meant to be under tyranny and absolute oppression. Understanding the suffering he had inflicted for millennia, he renounced his lust for conquest, officially disbanded the Decepticons, and voluntarily exiled himself into space to atone for his actions.