Leon S. Kennedy
Leon Scott Kennedy is one of two main protagonists in Resident Evil 2, and the central character featured in Resident Evil 4. In his initial appearance, Leon is a rookie officer employed by the Raccoon City Police Department amidst the T-Virus outbreak that would consume the city. In subsequent appearances, he is a well-trained, highly-skilled government agent specializing in the containment and elimination of bio-organic weapons.
Leon is showcased as a playable character in the non-canonical Game Boy Color title Resident Evil: Gaiden, and stands alongside fellow Raccoon City survivor Claire Redfield in the feature-length CG film Resident Evil: Degeneration. The story of his survival of the Raccoon City incident is recounted in Resident Evil: The Darkside Chronicles, and he is poised to be the protagonist of Capcom's sophomore CG film outing in Resident Evil: Damnation.
Resident Evil 2
Leon arrives in Raccoon City following the worst of the T-Virus outbreak, prepared for his first day on the job with the local police department's special forces unit. It doesn't take him long to figure out that something has gone pretty wrong; he is attacked by a group of infected citizens which leads him into a chance encounter with Claire Redfield. The two are separated following a car collision, but promise to meet up at the police station.
The precinct isn't as secure as Leon had hoped, and after the near-immediate passing of Marvin Branagh, Kennedy is left as the only surviving police officer in the city. However, with help from Branagh, Leon is able to rendezvous with Claire and decide on the game plan of searching out the building for survivors and escaping the city. This course of action leads him to Ada Wong, a tough-as-nails woman in search of her missing boyfriend, and Ben Bertolucci, a journalist. Leon's desire to perform well at his new profession pushes him to pursue Ada through Raccoon's massive sewer network, accessible from the dog kennel in the back of the police station. He is shot and wounded by Annette Birkin, but soldiers on and eventually stumbles into the Umbrella Corporation's underground research laboratory. It is here that Leon discovers that Ada is actually after the newly-developed G-Virus. She holds the officer at gunpoint, but ultimately chooses to spare his life just before she is shot and presumably killed herself by a fatally-wounded Annette. Before her death, Ada informs Leon of a train system constructed for the purposes of funneling Umbrella employees out of the facility in case of an emergency.
Before Leon can reach the train system, however, the self-destruct sequence is activated, and he is confronted by the mutated form of Umbrella top researcher and G-Virus creator William Birkin. He dispatches of the creature with relative ease and rushes aboard the already-moving train just before it departs entirely. Here he is reunited with Claire, and introduced to Sherry Birkin, daughter of the Umbrella researchers. Aboard the moving train, another mutation of William assaults them. The creature activates the train's own self-destruct mechanism, but the trio of survivors manage to escape, leaving William to die.
Resident Evil 4
Six years following the destruction of Raccoon City and the collapse of the Umbrella Corporation, Leon has become one of the government's top-performing agents, and is assigned to protecting the new President of the United States and his family. Ashley Graham, the president's daughter, is kidnapped and taken to a remote village in Spain. Leon is sent to track her down, and becomes involved in taking down a terror threat initiated by a group of fanatics calling themselves the Los Illuminados.
Leon receives some help in the form of Luis Sera, a native police officer, and manages to both locate and extract Ashley from her isolation. However, all attempts to pull the pair out of the area are met with extreme aggression from the Los Illuminados. Their leader, Lord Saddler, explains his plan to infect Ashley with the Las Plagas virus and send her back to the United States to provoke chaos. He also reveals that Leon himself has been infected with the same virus.
Luis, revealing himself as one of the researchers responsible for the creation of Las Plagas, attempts to cure both Leon and Ashley, but is abruptly killed by Saddler. Leon soldiers on, protecting his subject and escorting her through the various trips and traps laid out by the sadistic organization. When Ashley is abducted once again by the Los Illuminados, Leon is assisted by Ada Wong in finding her, confirming prior rumors that she is both alive and under the employ of Albert Wesker.
Leon is also confronted by Jack Krauser, the seasoned veteran having faked his death shortly after Operation Javier, and sought out Wesker's aid. He insults Leon for being blind to the kind of power that the Umbrella Corporation's research can instill into a human body, but despite all of his blustering, he is ultimately killed by his former partner.
Leon tracks Ashley to an island and again rescues her. The two manage to extract the Los Plagas from their bodies before confronting Saddler. Leon fares well against the cult leader, but his Plagas transformation is more than the skilled agent can handle. However, he is again assisted by Ada, who tosses him a rocket-propelled grenade launcher, with which Leon ends the Illuminados threat. Ada takes Saddler's Plagas sample from Leon at gunpoint, mirroring the events near the end of Resident Evil 2, but gives the agent the keys to her water ski. Leon and Ashley barely manage to escape the island before the self-destruct mechanism completes
Set in 2013, fifteen years after the Raccoon City Incident, President Adam Benford decides to reveal the truth behind the incident in Ivy University, Tall Oaks. But he is infected with the C-Virus and turned into a zombie before he can make the announcement. Leon is forced to shoot the zombified Adam in order to save his new partner, Helena Harper. Everyone then believes that it was Leon and Helena that killed the President, and they are forced to escape.
A man at the university guides Leon and Helena through the university in search of his daughter. They later find her, only for her to turn into a zombie and kill her father. Some time later, Hunnigan informs Leon and Helena that over 70,000 people have been infected with the C-Virus, and they were also informed that this virus has also been used by bio-terrorists in China and that it was the same virus used in Eastern Europe six months earlier. Leon then asks Hunnigan if she can fake their deaths so they can get to China and track down the people behind these outbreaks.
Leon manages to track down the woman behind the outbreaks, Ada Wong, but he is preceded by Chris and his partner Piers Nivans who has her surrounded at gunpoint. But just as Chris is ready to pull the trigger, Leon disarms Chirs, and after a brief struggle ending with both of them pulling their pistol on each other, Leon says this to Chris, "Put your gun down Chris, she's a key witness, we need her." Chris, clearly angry, says "A witness?! She's the one who did all this!"