WARNING: The following contains spoilers for Godzilla vs. Kong, now in theaters and streaming on HBO Max.
Godzilla vs. Kong has finally been released, letting viewers see the MonsterVerse's two kings duke it out in a battle royale. The latter definitely gets more screen time than the former, with Godzilla himself being somewhat of an antagonist in the movie. With so much impressive monster mayhem going on, there's definitely a focus on that instead of on the human cast.
The human characters include newcomer Ren Serizawa and Mark Russell, who's from the previous film. Despite Serizawa and Russell's supposed importance to the MonsterVerse films, both are barely used on screen in Godzilla vs. Kong, wasting them despite their potential.
Ren Serizawa
Ren Serizawa is introduced early on in the film as a scientist who works for Apex Cybernetics. As his name might suggest, he's the son of Ken Watanabe's Ishiro Serizawa from the previous Godzilla films in the MonsterVerse. Ishiro was one of the most important characters in the series so far, as his role was to explain the importance of respecting the Titans' power and to later sacrifice himself to resurrect a defeated Godzilla.
In spite of all of this, Ren's relationship to Ishiro is never a factor in the film. His philosophy is clearly the opposite of his father's, but his apparent antagonism toward the Titans is never explained. His own ambitions and reasons for working with Apex are also completely glossed over, and he's never made out to be as big of a deal as he narratively should be. He also never interacts with anyone who remembered his father, making his relation to Ishiro seem unnecessary.
His only role is to neuro-telepathically pilot MechaGodzilla, but even this minute use is quickly overturned when the machine he's hooked up to kills him, and Ghidorah takes over. For as much of a non-character as Godzilla vs. Kong made him, it would have been better if Ren literally was just a nameless goon without any fanfare, let alone a relation to one of the most iconic humans in the MonsterVerse.
Mark Russell
Mark Russell was essentially the protagonist of 2019's Godzilla: King of the Monsters, taking the reactionary "everyman" role over from Aaron Taylor-Johnson's character in the 2014 Godzilla. He had a vendetta against the Titans, namely Godzilla, due to his young son's death at the hands of the destruction they wrought. This only caused a rift between him and his wife and daughter, with his wife turning against humanity itself and freeing King Ghidorah.
Despite how central he was in that movie and how he was pretty much the only human character with any real development, he barely manages to get around two minutes of screentime in Godzilla vs Kong. These scenes involve him telling his daughter Madison not to seek out a conspiracy theorist, him mobilizing to Hong Kong and him meeting the conspiracy theorist at the movie's end. It's impossible to ignore how diminished his role is compared to his prominence in the preceding film, but King of the Monsters' reception may be behind this.
King of the Monsters was panned by many critics, and one of the biggest criticism was the bloated human cast, who were poorly developed and written. Mark and Madison are the only characters who debuted in King of the Monsters to make an appearance in Godzilla vs Kong, and it seems the criticisms of the past film played a part in that, with Mark's role being reduced significantly in favor of the titular monsters' battle.
Directed by Adam Wingard and written by Eric Pearson and Max Borenstein, Godzilla vs. Kong stars Alexander Skarsgard, Millie Bobby Brown, Rebecca Hall and Brian Tyree Henry. The film arrives in theaters and on HBO Max on March 31.