- See also: Kyle Reese (Original Timeline)
Kyle was born after Judgment Day. His parents told him many things prior to the catastrophe until they were killed.
Some time later, he was spotted by an Infiltrator in a sewage, but John Connor showed up and saved him by destroying the Terminator. Kyle recalled this was the first time that he learned a Terminator could be destroyed.
He then joined the Resistance unit known as Tech-Com under John Connor's command. They spent much time together not only as soldiers but also as friends. John gave him a snapshot of his mother, Sarah. They also tried to make distilled beverage but ended up blowing things up.
Before the Operation Chrono, John Connor asked Kyle to join his force to take down a prison camp which was more crucial than the other complex in Colorado as this camp contained the final weapon of Skynet in case it lost the war. John told Kyle that if he had a choice, he would rather not ask him to join his team for the mission.
After the Skynet was destroyed, the Resistance learned Skynet's plan of Sarah Connor's assassination. Many soldiers volunteered for the mission, but Kyle was the only one chosen for the mission to go to the year 1984 to protect Sarah Connor. Before the departure, Kyle asked John how could he know so much about every thing. John replied that it is because he "cheated". However, when seeing Kyle off, John was attacked by Skynet from behind, who infiltrates under the guise of a Tech-Com soldier Alex. As a result, Kyle gained memories of an alternate timeline.
After arriving in Los Angeles, 1984, Kyle was soon attacked by a T-1000, who was disguised as a police officer. He ran into Officer O'Brien and his partner, who was killed by the T-1000. Kyle managed to save O'Brien's life before both of them were saved by Sarah Connor.
Kyle was very shocked as Sarah, who was supposed to be saved, saved his life instead. Kyle was even more surprise when he saw the presence of "Pops", a Model 101 Terminator who was reprogrammed. Kyle was hostile toward Pops and immediately initiated a fight, Pops incapacitated Kyle. When Kyle woke up, Pops and Sarah explained to Kyle the changes to the future due to an attempt assassination of herself when she was 9 years old. In addition, they had been preparing for his arrival for over a decade.
The T-1000 tracked them down and, after a brief car chase, and found them in an abandoned warehouse. Upon arrival, the T-1000 impaled Pops with a pole through the shoulder, pinning and disabling it while the T-1000 went after Sarah, reactivating the T-800 to kill Kyle. Kyle managed to deactivate the T-800 once again and Sarah lured the T-1000 into an acid trap to dissolve it. Despite being badly damaged, the T-1000 managed to make it through the acid and strangled her, but by then Pops had freed himself, grabbing the T-1000 and holds it under the acid to dissolve it. However, doing this dissolved the skin on Pops' right arm before Sarah neutralized the acid so it would not damage his exoskeleton. Pops and Sarah then removed the T-800's CPU and dissolved its body in acid so it could not be found and used to create Skynet by reverse engineering as initially happened.
Pops and Sarah revealed to Kyle their plan: they intended to use the Time Displacement Equipment that they had developed to travel to 1997 to prevent Judgment Day by destroying Skynet before it was ever created. They needed the T-800's CPU to act as the time machine's operating system, but due to its damaged skin, which would take years to regrow, Pops could not make the trip as the magnetic field would destroy it. Pops chose to "take the long way" and prepare for their arrival instead. While preparing, Kyle remembered "Genisys" from his time jump and told Sarah and Pops about it. Pops confirmed it was possible that Kyle experienced the memories of an altered timeline by experiencing a nexus point while inside the machine and Sarah was convinced to jump forward to that time. Both Kyle and Sarah travelled to the year 2017 while Pops stayed behind alone, preparing for the task which would be needed in 2017.
When Sarah and Kyle arrived in 2017, Pops was not able to intercept them as they materialized above him on top of an overpass in the middle of traffic. Both of them were arrested. While in custody, they learned about an app called "Genisys", which Kyle remembered from his alternate memories that "Genisys" was a new form of Skynet. John Connor arrived the hospital and helped them escape. It seems that John traveled back in time right after Kyle did. It is during this time that John accidentally revealed to Kyle that Kyle is his father.
Pops showed up and shot John, revealing that John had been transformed into a T-3000 Terminator by Alex, who was Skynet from an alternate timeline. Sarah, Kyle, and Pops managed to escape John with Sarah noting that John Connor is no longer humanity's last hope, but Skynet's last hope. The trio went to a safe house to collect weapons in order to destroy Genisys. While stocking up, Kyle confronted Sarah about the fact that she lied to him about John's parentage. She told him that John was the one who really manipulated him as John did so to ensure his own existence. Kyle admitted to being in love with Sarah, but she pushed him away because she said that she was afraid that he would die like in the previous timeline.
John tracked them to their safe house and they proceeded to run from him using a stolen school bus. John attempted to kill them, but they survived and were arrested again. This time, they were helped by Detective O'Brien, who remember them from 1984 as he was saved by Kyle and Sarah. On the way out, they ran into the young Kyle Reese, who was afraid of all the gunshots. Sarah told him to run and not look back. After a helicopter chase with John, they went to the Cyberdyne building, where Genisys was being created. John came for them and almost killed them, but Pops slowed him down by trapping both of them in an electromagnetic field created by the prototype Time Displacement Equipment. While the two was struggling, Sarah and Kyle rigged the building with explosives. At the last minute, Pops was thrown into a pool of Mimetic polyalloy before John was killed by the electromagnetic field. Sarah and Kyle managed to find shelter in a bunker right as the building explodes. Trapped in the bunker, Sarah and Kyle believed they are about to die due to the lack of air, but they were saved by Pops, who had just been repaired and upgraded by the Mimetic polyalloy.
The trio went to the home of the young Kyle Reese, making sure he knew that Genisys is Skynet. This completed the loop for the adult Kyle's memories. Sarah mentioned that she could now choose the life she wanted before she and Kyle shared a kiss, indicating that she still chose to be with him. Sarah, Kyle, and Pops then drove off.
Kyle had a fight at the multiplex, causing his parents to show him what jail was like in an attempt to keep it from happening again, resulting in Kyle getting fingerprinted. After his older self from the future was arrested due to the incident on Golden Gate Bridge and his fingerprints matched the young Kyle's, Kyle and his parents were called upon to the police station to identify his older self. While Kyle had no idea who his older self was, he commented on his resemblance to Kyle's father.