Cole James Stewart was the brother of Liam Stewart and half-brother of Claire Stewart, and an agent of the Children's League. He was older than the age that scientists estimated was the cutoff for those who could have had IAAN, however, he developed Psionic abilities and was revealed to be a Red.
“They don't burn, do they? Not like us.”
-Cole, In the Afterlight
Cole is an important Children's League agent even before the events of Never Fade as he joined the League with Liam when they were children. He was a key agent in planning the attacks against Oasis and Thurmond. He was confident and cool although he doubted his capacity to control his Psi ability.
Cole is first introduced as Prisoner 27, the agent that Vida and Ruby were assigned to retrieve during the Op that opens the book. During this Op, Rob, a corrupted agent in the League, purposely plants a bomb below Vida and Ruby in order to kill them, but the plan backfires. They eventually rescue Cole and bring him back to the Children's League headquarters in Los Angeles. It is revealed that Cole had lost the hard drive that contained research on a possible cure for IAAN. Later in the book, he secretly assigns Ruby a mission. This is to break away from her Op team and find Liam and the hard drive.
Following the events of the last book, Cole forms an allegiance with Ruby to gather forces, supplies, and people to finally fight back against the rehabilitation camps and free the children inside. After the hit on Oasis, where Liam brings back the reporter Alice Waters from Amplify to the Ranch, it looks like Cole might kick his younger brother out. Eventually, he cools down and the kids and remaining agents split into teams for the newest Op. Cole takes Liam with him on a separate Op to investigate a Red camp named Sawtooth, after Cole discusses Project Jamboree with Clancy . They are spotted soon after breaking in and Cole is shot in the neck, dying instantly, after which he bound to a chair with a note saying ‘Try again’ and set on fire by the other Reds. All of this is seen through pictures sent from a cellphone to the Ranch.
Cole's true personality was extremely hard to assess. After witnessing his younger sister's death, he became bitter and guarded. During his time throughout the books, he was seen as a man who put off a lot of "macho bravado". He was a charmer as well. His faux confidence led Ruby to delve deep and try to understand why he was so guarded. In reality, his abilities scared him and he let this control him. He knew how to read a room and understood that the other Psi kids needed someone to look up to, so he stepped into that role. Cole deeply cared for everyone and wanted to protect them at all costs, presumably from the guilt of not being there for his sister. He made an impression on everybody and was compassionate and caring to those who knew him. Cole was finally coming to terms with his ability and told people his secret, only to die less than a day later.
Cole is described as tall, having a few inches on Liam, with close-cropped hair and bright blue eyes, and is almost identical to his brother -- so much so that Ruby is the only one able to accurately tell them apart.
Liam Stewart: brother
He and his brother, Liam, have a very strained relationship. They really wanted to have a normal relationship but could never see eye to eye. In spite of that, Liam is completely shocked and saddened when he dies, especially because he finally found out the reason behind Cole's secretive behavior less than a day before he died. Hence, Cole's death devastates Liam.
Ruby Daly: best friend and coworker
Ruby and Cole relate to each other as both of them have similar and extremely strong powers. Through the course of the series, they begin to trust each other and soon become best friends. Cole's words of encouragement and bravery come back to Ruby in one of her most difficult moments and act as a guiding light. Ruby keeps his dream alive by helping other kids like Cole.