Aselton returned as Amy briefly in the second season, when Jemaine Clement and Hamish Linklater were promoted from guest roles to series regulars and Navid Negahban joined the cast.
[1][2] Haller was diagnosed with schizophrenia at a young age and following a suicide attempt was placed into Clockworks Psychiatric Hospital, where he meets and falls in love with Syd Barrett.
After joining the Summerland group led by Melanie Bird, David is told that his schizophrenia was a lie, and he is in fact a powerful psychic mutant with advanced telepathic and telekinetic capabilities.
In the second season, after revealing his own true villainous nature and raping Syd, David goes on the run from Division 3 with Lenny as they set up a cult.
[2] Casting Stevens alleviated Hawley's concerns about focusing the series on David's internal issues, as "he's very vulnerable and also very strong" and can be endearing to the audience.
[3] Hawley created a 160-track playlist to help Stevens understand David's mindset, which included "everything from experimental French sound design, people screaming into bins and such, to Pink Floyd and everything in between.
[6] David's earlier life is shown in several flashbacks and dream sequences,[7] with the character portrayed by Tobias Austen and Noah Hegglin Houben as an infant, Sebastian Billinsley-Rodriguez as a toddler, Christian Convery as a four-year-old, Luke Roessler as a six-to-eight-year-old, Jacob Hoppenbrouwer as a ten-to-twelve-year-old, and Alex Mulgrew as a sixteen-year-old.
Sydney "Syd" Barrett (portrayed by Rachel Keller)[1][2] is a mutant with the power to involuntarily body-swap with anyone she makes skin contact with.
Though she is aware of the nature of her powers from young age, she is treated in Clockworks Psychiatric Hospital for her manic refusal to make tactile contact with anyone.
[9] The character is named after Roger "Syd" Barrett of the rock band Pink Floyd, whose music was an important influence on the series for Hawley.
[1][2] She is treated in Clockworks Psychiatric Hospital alongside him, and killed in the first episode when Syd Barrett switches bodies with David and accidentally loses control of his powers.
The amount of distress caused by the Time Eaters, experiencing living a life and raising their child up until their natural death in a matter of minutes, leads Lenny to committing suicide by stabbing herself in the neck.
While preparing for the role, Plaza decided that Busker's hands would be covered with small henna tattoos, which had to be applied every day before filming.
[16][2] Hawley "had to pitch him the weird, crazy character dynamic and that the show is about memory and identity", and Irwin agreed to join the project.
Amy Haller (portrayed by Katie Aselton) is David's older sister, who tries to remain positive despite his history of mental illness.
Melanie Bird (portrayed by Jean Smart) is a demanding psychiatric therapist who uses "unconventional" methods[1][15] to assist mutants, while also offering them protection by hiding them from the Government Division 3 in Summerland.
In the third season, Melanie and Oliver are shown in the Astral Plane where they get Syd's lost mind back to its current age while contending with Wolf.
[22][23] In July 2017, Hawley announced that Saïd Taghmaoui had joined the cast for the second season, and would portray the Shadow King's true form, Amahl Farouk.
[24] In November, during production on the season, Taghmaoui announced that he was no longer involved with the series, and FX confirmed that "a decision was made to recast" the role of Farouk.
[28] Negahban had just completed work on Aladdin (2019) when Hawley contacted him about taking on the role, and he watched the first season of the series during a weekend before joining the production.
Negahban worked with the other actors, including Stevens and Plaza, to track the development of the Shadow King through the series,[29] and was given a map by the writers that helped explain his character's backstory.
[30] The Devil with the Yellow Eyes (portrayed by Quinton Boisclair) is a grotesque creature that haunts Haller, one of the forms of the Shadow King.
Boisclair was cast as the Devil with the Yellow Eyes for his physique, with Hawley describing him as "just someone they found at a comic book store who happened to be 6'8" and very skinny.
Like David, he appears to possess vast psychic/reality warping powers, making him able to manipulate the Astral Plane at will, and manifest himself, and move objects, in the physical world, miles from his actual body.
In the third season, Oliver and Melanie are shown in the Astral Plane where they get Syd's lost mind back to its current age while contending with Wolf.
Hawley announced in October 2016 that Jemaine Clement would be joining the series in what was described as "a multi-episode arc",[32] later revealed to be portraying Melanie's husband Oliver.
In light of the Shadow King's threat, Melanie persuades Clark to contact his superiors to call a truce between Summerland and Division 3.
When David and his cult raid the airship to rescue Switch, Clark and the security personnel are teleported into space where his body freezes.
Hamm agreed to take on the role,[37] and Hawley thought he gave the segments "such character", comparing the final performance to Rod Serling.
[37] The robot-like Vermillion who appear as women with mustaches are portrayed by Jenna Borrenpohl, Jelly Howie, Ashli Dowling, Caitlin Leahy, Brittney Parker Rose, and Lexa Gluck.