Sigma Klim

Dr. Sigma Klim is the first-person protagonist, and antagonist, of Zero Escape: Virtue's Last Reward. He is taken from the Hard Ending epilogue, when 67-year-old Sigma returns to his proper body. He is played by World.

Background
The game opens with Sigma being kidnapped from his university on Christmas day and gassed with a powerful anesthetic. When he awoke, he was informed that he and eight others would be participants in a life-or-death game called the "Nonary Game: Ambidex Edition," run by a man named Zero.

The Ambidex Game was a game intended for psychological torture, based on the Prisoner's Dilemma. On their left wrists were attached bracelets with a score on the display. Each person's score began at 3 -  the first participants to 9 Points would be allowed to escape through the Number Nine Door in the facility, which only opened once. The losers were either to be killed by a virus that caused hysteria and self-mutilation (if they were left behind when the door shut), or euthanasia (if their points hit 0 or negative). Points were scored or lost by teaming up and either choosing to ally (2 points to each participant) or betraying (3 points to the betrayer, -2 points to the betrayed OR 0 points if both players choose to betray) their partners.

There are only two endings out of 27 where Sigma wins the Ambidex Game. In one, he must betray his partners twice, and leave with fellow participants Phi and Dio. In another, the True ending, he must disarm 4 bombs, convince every player to Ally, and escape with every participant at once. In the rest, he is either euthanized, murdered, or commits suicide.

In the True Ending, Sigma eventually discovers that he is an esper, and can see every Quantum timeline where he died or was injured, have premonitions of the future, and even time travel. Once his powers are strong enough (they are bolstered each time he or someone else dies in any timeline), he can disarm the 4 bombs that he learned the disarming codes to in other universes he has forseen.

Sigma also discovers that he is not in his 22-year-old body. Looking into a pool of water, he learns that he has jumped 45 years into the future: his body is 67 years old. He was brought into the future by Zero so that he could learn of his powers, and go back in time to the day he was kidnapped (Christmas 2028) to prevent the extinction of humanity six days later (New Year's Eve 2028). Zero is actually Sigma Klim as an old man, and the two of them have exchanged places: Zero was currently occupying his body in the past.

Sigma returns to his 22-year-old body in the past to learn that Zero failed to stop humanity's extinction. In the process, both of his arms and eye were torn out and replaced with titanium cybernetic prosthetics. Now one of the only human beings alive, he is instructed by the “villain” of Zero Escape: 9 Hours 9 Persons 9 Doors, Akane Kurashiki, that he must complete the time loop: he must spend the next 45 years of his life engineering the Nonary Game in hopes that 45 years from now when he exchanges places with the 22-year-old version of himself on Christmas Day, he will not fail. If he choses not to go through with the plan, there will be no chance that the world will be saved - and most likely, the timeline would collapse.

Sigma is forced to agree. He becomes Zero, is locked in a facility on the moon for 45 years, and recreates the Nonary Game from memory, exactly as he had played it. He also personally finds and kidnaps the 8 other participants he had played it with. During his time on the moon, he meets a fellow survivor named Diana and falls in love with her. They become a couple, but years into their relationship she dies of heart disease. Heartbroken, Sigma creates a robot with her appearance and personality, named Luna, in her memory. As part of the project, Sigma also becomes a nobel-laureated-equivalent geneticist, as well as a doctor in computer programming and mechanical engineering, so that he can create the traps and give life to one of the participants he had played with during the game: a clone of himself.

At age 45, his son and clone, Kyle Klim, is born. Over the years, he becomes extremely fond of Kyle, and Sigma realizes that his love for Kyle makes it difficult for him to jump into the past and leave his son behind.

On January 27th, 2074, Sigma trades places with his 22-year-old self and jumps back in time to December 25th, 2028. His best friend Phi comes with him.Sigma attempts to stop the cause of humanity's extinction, a bio-engineered virus named Radical-6, from being released. They attempt to infiltrate the government facility where it escaped, but it was rigged with deadly traps.

During their infiltration, one of the traps endangers one of the people at the facility. She is Diana, the love of his life who had been his only companion in his first years on the moon. Knowing that he cannot allow another innocent person to die on his behalf, he saves Diana by taking her place, losing his arms and his eye in the resulting explosion. The virus escapes and humanity goes extinct. The time loop becomes a perfect circle.

When 22-year-old Sigma is sent back into the past to his normal body, 67-year-old Sigma switches places with him and returns to the ending of the Nonary Game in the future. Exhausted and unable to cope with his failure, he locks himself in his room. The credits roll.

Personality
Sigma's personality, though it may appear refined, is best described as "Chad." As a young man, Sigma was extremely melodramatic. He had a tendency to overreact to everything, good and bad. Fortunately, older Sigma is slightly more mellow; however, he is still the same man, and has moments where his relaxed persona breaks down. There is an instance where he gets frustrated with Kyle and mocks his young son for being a "whiner", making him cry. As well, when he and Kyle have a severe fight when Kyle grows up, Sigma chooses to sedate Kyle and lock him up in a room as a solution to the problem, an extremely unnecesary action for a parent. And after the events of Virtue’s Last Reward, Sigma choses to hide himself rather than accept the company of the people who care for him.

While Akane goes on about how much Sigma loves Kyle, when younger Sigma speaks with Kyle, Kyle tells him how distant his father was and how easy it was to pretend that the two of them didn't live in the same place. He mentions that he never got the sense that his father cared about him, because his father barely ever touched or held him. Kyle also mentions that Sigma never ate with him because Sigma honestly never thought it was necessary to. When they did begin to eat together, Akane frequently had to scold Sigma at the dinner table, because he would absorb himself in research papers and forget to eat or even acknowledge the presence of his family.

But inwardly, Sigma is nowhere near as cold and distant as he seems. Compared to the warm and friendly Akane, who, as the writer has said, "is a much darker person on the inside and is prepared to murder to accomplish her goals," Sigma has a much straighter moral compass. While Akane as Zero I brutally murders people in her version of the Nonary Game, the True Ending of Sigma's Nonary Game has no fatalities. Sigma, due to his powers to jump through time and space, holds an almost religious belief that humans must be apart of one single, even godlike entity, and no single life is more or less important than another.

He also is very kindhearted and noble. When faced with danger, Sigma puts the safety of others above his own. In one ending, Sigma sacrifices his life to save a sick child. In Kyle's Ending, Kyle, Phi and Sigma lose the Nonary Game and are euthanized. Kyle and Phi fall unconscious, but Sigma manages to find medicine to save one person. It only takes him a moment to decide between saving Kyle or Phi - he does not even consider saving his own life to be an option. He chooses Phi, only because Kyle is wearing heavy armour that Sigma cannot remove or get the needle through, and while Phi is healing, he chooses to die at Kyle's side. He also never purposefully harms anyone, though most of the other participants use deadly violence as a means of solving their differences.

But Sigma's odd personality may be explained by his inability to relate to others very well. Though he is a usually thoughtful, emotional person himself, he has a hard time reading the emotions of other people and is unable to tell if they are being genuine or not. Because of this, his kindness often leads him to be too trusting and give the person the benefit of the doubt, leading to him being used or even killed on more than one occasion. He also has a hard time realizing when the people around him are uncomfortable or unhappy.

In the Arena
In Arena 05, Sigma survived the Cornucopia after a fight with Howard Bassem, and made an alliance with Howard and Eponine Thenardier shortly before Eponine's death. Sigma later hid in a crevasse, where he saved the life of Alex Rider, having forseen his death in a vision. While looking for food, he also rescues Cassandra Marko from a bird attack. Returning to the crevasse, Sigma and Alex fall victim to a glacier collapse. Sigma tries to pull himself to safety, but when Alex grabs his hand, Alex loses his grip. Sigma falls and is killed.

In Arena 06, Sigma attacked Donatello Hamato at the Cornucopia, ripping off the other Tribute's arm in revenge for Kyle's death in the previous Arena. He suffers a broken rib and a sprained ankle in the process. As Sigma hides, he meets Beck, Kyle and Howard. Howard brings him a cat to eat, but Sigma refuses, adopting the animal instead. Later, Kyle and Sigma split up to search for food, and Sigma runs into Don. To prevent Donatello from finding Kyle, Sigma attacks him, and the two stab eachother to death.

In Arena 07, Sigma was poisoned at the Cornucopia. During his death, he was found by Neffa de Reyeth, who attempted to help Sigma to no avail. In an attempt to get Neffa to flee, Sigma tried to stand and run, but was brought down by the poison. Kyle, returning from the Cornucopia, then discovered his father's body and held him. Relieved his son was still alive, Sigma died in Kyle's arms.

In part 2 of Arena 07, Sigma awoke in the desert Arena. He was greeted by Ian Gallagher, to whom he offered water that was refused. Sigma later met up with Orc, who had discovered one of the televisions that broadcast the happenings of the original Arena, and Eponine, with whom Sigma formed a close bond. Later, Sigma was saved from a coyote attack by R. However, some time later he found Maximus trying to kill Eponine to feed R. Enraged, Sigma rushed to her defense, and he and Eponine were killed and eaten.

In Arena 08, Sigma grew ill after catching Howard Bassem's flu. He allied with Eva Salazar to take care of Eponine, who was also ill and had sustained an injury. Eva left to hunt for food, and when Sigma was supposed to be watching Eponine, he fell asleep and the girl ran away. Ashamed, Sigma abandoned his post and encountered The Grand Highblood, who, owing Sigma a favour, escorted him to safety. He was then found by Homura Akemi, who mercy killed him before his condition could worsen.

In Arena 09, Sigma made use of the masks that restored his powers in order to help whom he could. This plan backfired spectacularly when he foresaw Donatello being killed by Terezi Pyrope, and sacrificed himself on a whim in order to save him. Angry at himself, Sigma died realizing he should have used his powers to protect Howard, who later died.

Abilities

 * Sigma is a Time Traveller, but those abilities have been permanently nerfed in-game.
 * Sigma has a eidetic memory, and can recite or recreate anything he's seen or heard in his life perfectly.
 * Sigma has cybernetic titanium arms, which are shown to have increased strength. They are made of artificial skin called "ABT," and white ABT fluid acts as blood. These arms can be injured or bleed out without causing him much harm.
 * He also has a cybernetic eye, which can zoom in on objects at a distance.
 * Under gamemaker control: He can see some Quantum universes where he or another person was killed or harmed, therefore giving him the power of foresight.

Miscellaneous

 * Sigma has an odd tic where if cats are mentioned, he will talk in nothing but cat puns for the rest of the conversation.
 * Young Sigma and Kyle are voiced by Troy Baker (Kanji Tatsumi, Booker deWitt) in the US version and Kosuke Toriumi (Junpei Iori, Yuri Lowell) in the Japanese. Older Sigma is voiced by Jamieson Price (Reeve Tuesti, Yasutoru Sado) in the US version, and Akio Otsuka (Solid Snake, Black Jack) in the Japanese version. He is voiced by Matt Mercer in Zero Time Dilemma.