Here's why the MonsterVerse killed off Dr. Vivienne Graham (Sally Hawkins) in Godzilla: King of the Monsters. Dr. Graham was one of three returning characters from 2014's Godzilla in the 2019 sequel. Admiral Stenz (David Straithairn) came back for a much smaller role, with Vivienne and Dr. Serizawa (Ken Watanabe) both taking part in the mission to stop Jonah (Charles Dance) from using the Orca to wake up the Titans.
Similar to her presence in the 2014 Godzilla film, Vivienne acts as a Monarch scientist who accompanies Dr. Serizawa, while at the same time providing input on the Titans, the abduction of Emma (Vera Farmiga) and Madison (Millie Bobby Brown), and more. She's also shown to be a friend to the film's human protagonist, Mark (Kyle Chandler), and lends him a sympathetic ear. She doesn't stick around for the whole movie, though, as she meets her end in the first half of the film when King Ghidorah awakens from his frozen slumber in Antarctica.
It was during Ghidorah's attack that Vivienne was killed. She and Mark were running when one of Ghidorah's three heads swooped in and devoured her, with both Mark and Serizawa watching in horror. Godzilla: King of the Monsters director Mike Dougherty has revealed that Vivienne's death served a narrative purpose. According to Dougherty, the intention was to express the "ruthless brutality" of Ghidorah. For this to happen, a character had to be killed off, and it wouldn't have mattered as much to audiences if Ghidorah had eaten one of the new characters or an extra [via Twitter].
It was certainly a sad moment, made even sadder by the fact that fellow Godzilla character Dr. Serizawa died later in the film, thereby killing off the two people who audiences most associated with Monarch and two of the only three characters who returned from the 2014 film. Regardless, Vivienne's death did help get the point across that Ghidorah isn't like other Titans. Ghidorah is cruel in ways that creatures like the M.U.T.O.s. and Rodan are not. These Titans have killed as well, but Ghidorah has killed needlessly and without provocation. This also plays into the idea that Ghidorah's heads all have their own personalities; one, in particular, the right head, is more aggressive than the others.
Doughtery claims that some have said that Ghidorah wouldn't have wasted his time on one human, but Ghidorah is a "genuinely sadistic" creature who "enjoys" what he does. This is an important aspect of his character, and the Titan's actions in Antarctica are demonstrative of that. It's also one more thing that makes Ghidorah stand out from the rest of the Titans. As it turns out, Ghidorah's differences are essential to the plot. Not only is he evil, but he's also willing to terraform the planet, and is seemingly immune to the effects of the Oxygen Destroyer. All of Ghidorah's unique qualities apparently stem from his alien nature. As an alien invader from a distant planet - just as he was in the classic Toho movies - Ghidorah was able to pose a tremendous challenge to Godzilla. It's just unfortunate that one of the 2014 Godzilla's returning characters had to receive such an unceremonious death at his hands.
