Role in the God of War series:
Throughout the series, Kratos is portrayed as an antihero,often performing questionable actions. Although backstory is seen in the original God of War, Kratos' childhood is revealed in Ghost of Sparta and the birth of his daughter is explored in the God of War comic series. In Ghost of Sparta, it is revealed that an oracle had foretold that the demise of Olympus would not happen by the hands of the Titans—imprisoned after the Great War—but rather by a mortal, a marked warrior. The Olympians Zeus and Ares believed this warrior to be Deimos, Kratos' younger brother, who had strange birthmarks. Ares interrupted the childhood training of Kratos and Deimos in Sparta and kidnapped Deimos. Kratos attempted to stop Ares, but Ares swept him aside and scarred him across his right eye. Taken to Death's Domain, Deimos was imprisoned and tortured for many years by the god of death, Thanatos. Believing Deimos to be dead, Kratos marked himself with a red tattoo, identical to his brother's birthmark, to honor his sibling.
Through flashbacks in the comic series written by Marv Wolfman, Kratos meets his wife Lysandra and they have a daughter named Calliope. Upon birth, Calliope was stricken with the plague. In order to save his daughter, Kratos was granted a quest to find the Ambrosia of Asclepius, an elixir with magical healing properties. Five of the gods entered into a wager with Ares: each chose a champion to search for the Ambrosia with Ares' champion being Kratos. Kratos overcame all obstacles, including, among others, Hades' champion, the Barbarian Prince Alrik who eventually became the Barbarian King, and thus Kratos saved his daughter.
Via flashbacks in God of War, it is revealed that Kratos became the youngest captain of Sparta's army (also shown in the comics), but had a thirst for power. When Kratos was faced with total defeat at the hands of a barbarian horde led by the Barbarian King, the Spartan called to the Olympian god Ares for aid. Kratos was given the Blades of Chaos, destroyed his enemies, and blindly followed Ares, killing hundreds in his name. After Ares tricked Kratos into murdering his wife Lysandra and daughter Calliope in a temple dedicated to Athena, the Spartan was shocked out of his bloodlust and renounced service to Ares. As the temple burned, a village oracle cursed Kratos and condemned him to wear the "mark of his terrible deed"; the ashes of his family, which turn his skin white, earning him the title "Ghost of Sparta".
Ascension, Chains of Olympus, and God of War (2005)
In Ascension, it is revealed that because Kratos renounced Ares, it broke his blood oath to the god and as such, Kratos was imprisoned and tortured by the three Furies. He was helped by the oath keeper Orkos and eventually overcame and killed the Furies. In order to completely be free of Ares' oath, Kratos was forced to kill Orkos, who begged Kratos to do so. Although free of his oath to the god, he was flooded with memories of killing his family. He then vowed to serve the other gods in order to receive forgiveness and relief from the nightmares of his past deeds, but he was openly defiant.
In Chains of Olympus, Kratos was reluctant to help the gods when Helios was kidnapped, and openly abandoned them when Persephone offered him a chance to be reunited with his daughter. Kratos, however, was forced to reverse his decision when Persephone used the Titan Atlas in a bid to destroy the world and in turn, the spirit of Calliope. Knowing that while intervention would save Calliope, it would separate him from his family forever, a bitter Kratos killed Persephone, imprisoned Atlas, and freed Helios.
By the time of God of War, Kratos had been serving the gods for ten years and had grown tired of his service and nightmares. When he confronted his patron Athena, she advised him that if he killed the rampaging Ares, the gods would forgive his sins. With this selfish motive, he again agreed, and after finding and using Pandora's Box, he was successful. Despite being freed of Ares' influence, including the Blades of Chaos, Kratos was forgiven but was not relieved of his nightmares. A dissatisfied and despairing Kratos tried to commit suicide but was saved by Athena, who guided him to Olympus. Awarded the Blades of Athena, Kratos became the new God of War.
Comics (present), Ghost of Sparta, and Betrayal
The comic series also shows Kratos' present search for the Ambrosia of Asclepius. This time, he plans to destroy the Ambrosia to prevent the worshipers of Ares from resurrecting their former master. In this quest, Kratos overcame several enemies, including the Chaos Giant Gyges, before destroying the Ambrosia. Still haunted by the visions of his mortal past in Ghost of Sparta, and against the advice of Athena, Kratos embarked on a quest to find his mother, Callisto, in the city of Atlantis. Callisto attempted to reveal the identity of Kratos' father before being transformed against her will into a beast that Kratos was forced to kill. Before dying, Callisto advised Kratos to search for his brother Deimos in Sparta. Kratos first freed the Titan Thera from imprisonment, which caused the destruction of Atlantis. In Sparta, Kratos learned of Deimos' location: the Domain of Death. He found and freed Deimos, who remained hostile toward his brother. After a skirmish between the siblings, Thanatos attacked Deimos, but after being rescued by Kratos, the pair joined forces to battle their foe. Although Thanatos killed Deimos, the god was in turn killed by Kratos. Kratos then returned to Olympus, enraged at the gods. In Betrayal, Kratos had been shunned by the other gods and decided to lead his Spartan army to overrun Greece. He was falsely accused of murdering Argos, and he killed Ceryx, the son of Hermes, for interfering in his search for the true assassin, who escaped.
God of War II
Kratos then joined the Spartan army in Rhodes, intent on destruction. Zeus, however, weakened Kratos and tricked him into abandoning his godly powers into the Blade of Olympus, which Zeus used to kill Kratos. Although he overcame all obstacles, Kratos was stunned at Zeus's betrayal and swore revenge as he died. Kratos fell into the Underworld, but was rescued by the Titan Gaia. Banished to Tartarus with the other surviving Titans after the First Great War, Gaia and her brethren seek the death of Zeus. Kratos, fueled by anger at his betrayal, agreed to aid the Titans and was instructed to find the Sisters of Fate, who are capable of returning him to the moment of Zeus' treachery. Kratos became determined and utterly ruthless—in the pursuit of his goal he wounded a Titan, killed several Greek heroes without hesitation, and deliberately sacrificed two scholars. All three of the Sisters of Fate were killed when they opposed Kratos, who was prepared to kill Zeus in a final confrontation. Zeus was only saved when Athena intervened and sacrificed herself for him; only then does Kratos show remorse. He learned from a dying Athena that Zeus is, in fact, his father, a fact Zeus kept secret because he wished to avoid a repetition of what he did to his own father, Cronos. Kratos rejected any notion of a relationship and vowed to kill Zeus and destroy Olympus. Encouraged by Gaia, Kratos used the power of the Fates to retrieve the Titans before their defeat in the Great War, and with their assistance, stormed Mount Olympus.
God of War III
Although Kratos killed Poseidon, he was abandoned by Gaia when his first encounter with Zeus went poorly. Stranded in the Underworld and now betrayed by both the Olympians and Titans, Kratos learned from the spirit of Athena, who also provided the Blades of Exile, that he needed to find the Flame of Olympus, which is the key to defeating Zeus. Kratos murdered both Titans and gods, ignoring the warnings of his victims as he sought the Flame. Realizing the key to pacifying the Flame and reaching Pandora's Box (engulfed by the Flame) is Pandora herself, Kratos came to care for Pandora, who reminded him of his lost daughter Calliope. Kratos showed humanity when he attempted to stop Pandora from sacrificing herself to quench the Flame, but reluctantly allowed the act when she said there was no other option. Finding the box empty, and driven berserk by Zeus' mockery, Kratos attacked his father. Although Gaia interrupted and tried to kill Kratos and Zeus, she was destroyed by Kratos, who then apparently defeated Zeus. Zeus returned in spirit form and attacked Kratos, who retreated into his psyche. Kratos forgave himself for his past sins with the help of Lysandra. Pandora later appeared and told Kratos that hope would save him. Kratos was revived and easily destroyed Zeus. Athena confronted Kratos and demanded that he return the power of hope; the contents of Pandora's Box. In a selfless act, Kratos refused, stated his need for vengeance was gone and impaled himself with the Blade of Olympus, which dispersed the power across the world for mankind's use. Athena, disappointed with Kratos, removed the Blade and departed as Kratos collapsed next to the Blade of Olympus. The post-credits scene showed a trail of blood leading away from the Blade with Kratos' whereabouts unknown.
God of War (2018)
Many years after the events of God of War III, Kratos has ended up in Midgard with a young son named Atreus, who is unaware of his true nature. Kratos has abandoned his double-chained blades, and uses a magical battle axe called the Leviathan Axe that originally belonged to his second wife and Atreus' mother Laufey, who recently passed and who Kratos called Fey. Her last wish was for her ashes to be spread at the highest peak of the nine realms. At Midgard's peak, they learn from Mímir that the highest peak is actually in Jötunheim. Along their journey, they are confronted by the Æsir god Baldur, the brother of Thor whose sons Modi and Magni assist their uncle, but are killed by Kratos and Atreus. Around this time, Atreus falls ill, and Kratos reveals to him that he is a god. Kratos also recovers his old weapons, the Blades of Chaos, in order to battle the beings of Helheim as Nordic weapons and magic are useless there. While retrieving the blades, Athena appears and goads him about his past. The pair also receive assistance from a Witch, later revealed to be the Vanir god Freya, the mother of Baldur who had cast a spell of immortality on Baldur to protect him, but it also caused him to no longer feel pain or pleasure, which he resented her for. Kratos and Baldur eventually battle, during which, Baldur's spell is broken. Kratos decides to let Baldur go, but Baldur attempts to kill Freya, forcing Kratos to kill him. Freya swears revenge against Kratos for killing her son and taunts Kratos for not revealing his troubled past to Atreus. Kratos decides to tell Atreus that he had killed his fellow Greek gods, including his father Zeus, but he and Atreus should learn from these experiences and not repeat past mistakes. The two then make their way to Jötunheim, where it is learned that Faye was actually a giant, also making Atreus part-giant. It is also revealed that Faye had originally named their son Loki, but Kratos preferred Atreus, which was the name of an honorable Spartan comrade. In Midgard, Fimbulwinter began, and after returning home, Atreus has a vision that Thor will come for them at the end of Fimbulwinter.