Transformers: Age of Extinction made a very pivotal change to the origins of Galvatron, which ultimately ended up hurting Michael Bay's live-action Transformers franchise. In the film, Galvatron was the result of the efforts of the company KSI, run by Joshua Joyce (Stanley Tucci), to create an army of Transformers using the metallic alloy "Transformium." Galvatron was created with the help of the destroyed Megatron's head, with this new Transformer becoming a reincarnation of the character.
The origin of Galvatron in Transformers: Age of Extinction differed significantly from the character's original cartoon origins in 1986's Transformers: The Movie, who was a reborn, reconstituted Megatron. Transformers: Age of Extinction screenwriter Ehren Kruger wanted to pay homage to this original origin for Galvatron but also went in a new direction by making the character a human creation. This ended up hampering the movies and franchise since Galvatron was far scarier when he was not a human-based creation. It was a missed opportunity not to stay faithful to the original backstory.
Galvatron's Cartoon Backstory Explained
The first act of Transformers: The Movie ends with a final battle between Optimus Prime (Peter Cullen) and Megatron (Frank Welker), which ends with both becoming mortally wounded. Megatron was discarded into space by the treacherous Starscream (Chris Latta) and was found by the film's planet-devouring villain Unicron (Orson Welles). Unicron gave Megatron a new body in exchange for destroying the Matrix of Leadership. He was reborn as Galvatron (Leonard Nimoy), who promptly killed Starscream and resumed control of the Deceptions.
How Galvatron's Cartoon Backstory Would've Changed Transformers: Age of Extinction
The origin of Galvatron was changed for Transformers: Age of Extinction since the Michael Bay movies needed to have their own distinct identity. However, the character factored very little in the film's plot since the Cybertronian assassin Lockdown (Mark Ryan) was the film's lead antagonist. When the character returned in Transformers: The Last Knight, he was back to being called Megatron. This was a major missed opportunity for the live-action Transformers franchise since staying true to Galvatron's cartoon backstory would have also opened up the chance to introduce Unicron as a possible antagonist, negating the need for human villains such as Joshua Joyce and KSI. While Transformers: The Last Knight finally alluded to Unicron, it was with the puzzling revelation that the planet-devouring Transformer is Earth itself.
One thing that Transformers: Age of Extinction got right about Galvatron's origin was the change in voice actor to signify that he's a reborn character. In this case, it offered the opportunity for original Megatron voice actor Frank Welker to return to the role after Hugo Weaving voiced the character for the first three Transformers films. While this worked well as fan service, Frank Welker's casting was too little, too late, as Transformers: Age of Extinction marked the point when the live-action franchise moved past its prime.