Mark
Mark is a teenage boy who is the protagonist of The Kill Order. He is close with Trina, who was his neighbor growing up. He is also very close with Alec, who is like a paternal figure to him. Mark is physically fit, kind-hearted, caring, and fiercely protective of his friends. His friends have become his family after the sun flares killed off everyone else they loved. He had a younger sister named Madison for whom he cared greatly. Mark eventually succumbs to the Flare, but not before helping Deedee escape to safety. Mark shows remarkable bravery throughout the entire story.
Alec
Alec is a key character who functions as Mark's partner in their adventures and discoveries in the story. Alec was an ex-soldier, and his soldier skills and reflexes come in handy all of the time. He is also Mark's mentor, teaching the younger man all that he knows. Alec was the one who saved Mark and Trina from the subtrans tunnels the day the flares struck, and if it were not for him, the group of friends probably would not have survived. He is very close friends with Lana, with whom he used to work. Alec is heroic and noble.
Trina
Mark's neighbor, friend, and love interest. Trina is a beautiful teenager girl with cropped, short, blond hair. She is kind-hearted and caring, and especially fond and protective of Deedee. She and Mark are very close, and they spend their last moments together.
Lana
Lana is Alec's best friend and former coworker. Lana was an ex-army nurse, and her own toughness and bravery are also reflected in the ways that she takes care of the group. Lana is unfortunately captured by crazy infected people and beaten violently. As a result, Alec has to put her out of her misery. She is reflective and knowledgeable.
Darnell
Darnell is one of the "three Stooges," along with Misty and the Toad. He is one of Mark's friends. Darnell is the first person to succumb to the Flare's mutated effects. He goes crazy and kills himself as a result, instead of dying immediately.
Misty
Misty is one of the "three Stooges," along with Darnell and the Toad. She is one of Mark's friends. Misty is the second person in their friend group to succumb to the Flare's mutated effects. She stays behind, but gives the infection to the Toad, who had to put his best friend out of her misery.
The Toad
The Toad is one of the "three Stooges," along with Darnell and Misty. He is one of Mark's friends. 'The Toad' is his nickname, given by his best friend Misty. The Toad is the third person in their friend group to succumb to the Flare's mutated effects. As a result, Alec has to put the Toad out of his misery.
Deedee
A four- or five-year-old girl who was left behind in her village because she was immune to the Flare virus. She is picked up by Mark and his friends. Because of her immunity, Mark and his friends realize that she could be of help to government officials and finding a cure, so they send her to the government headquarters at the end of the story. She is close with Trina. She is renamed Teresa after she is taken in by WICKED; she is the same Teresa Agnes from the Maze Runner trilogy.
Jedidiah
The former leader of Deedee's village. He is deformed and has no ears. He has become a cultish leader, believing that the Flare is a punishment from celestial demons. He dies from the Flare.
Bruce
A former government employee. He and his team were deployed to test the Flare on Deedee's village and Mark's area. However, after the disastrous effects, he and his team were largely abandoned by the top bureaucrats. He and his team are also infected by the Flare, and they plan on storming the nearby city of Asheville to fight the government for a cure.
Anton
One of Bruce's colleagues. He disagrees with their crazed plan to storm the government, and left them because they gave Deedee back to the infected villagers. He gives Alec and Mark information when Alec and Mark are still trying to figure out what is going on.
Baxter
Originally a member of Mark's group of friends. Baxter was gunned down by a scavenger when the friends were hiding in the Lincoln Building. He only appears in Mark's flashbacks.
Boss
A scavenger who comes into conflict with Mark and his friends when they are camped out in the Lincoln Building after the Flares. He guns down Baxter as a show of his power. He makes Mark and his friends stock up his boat, but Mark and his friends manage to kill him and take over his boat and supplies.
Madison
Mark's younger sister who died in the sun flares. Deedee often reminds Mark of her.
Katie McVoy
A government official who comes up with the idea of using the virus as a population control mechanism. When this plan backfires, McVoy becomes a key player in WICKED. She introduces Teresa and Thomas to each other, using them as Immune children leaders to help her and WICKED build the Maze and run the Trials.
Chancellor John Michael
The Chancellor at the time that the Flare is released. He is the one who believes that population control must happen, and the one who sanctions Katie McVoy's plan to use the virus.
Ladena Lichliter
A government employee who is also then a WICKED employee. She leads Teresa out of her room to meet with Thomas when WICKED wants to use the two of them.
