Kratos' story begins approximately 4,000 years before the events of Tales of Symphonia. He was the only human companion of the hero Mithos Yggdrasill, and traveled the world with him, putting an end to the Kharlan War, which spanned one-thousand years. During these adventures, Mithos formed pacts with each of the Summon Spirits throughout the world. After forming the pact with the King of Summon Spirits, Origin, a seal based on Kratos prevented anyone from gaining this power. Essentially, the seal can only be broken once Kratos's mana is released, thus ending his life. Mithos then had Origin create the Eternal Sword, which he used to split the world in two, thereby creating Sylvarant and Tethe'alla.
Shortly after Mithos, Kratos, Yuan Ka-Fai and Martel ended the war, they were betrayed by a human who had aided them during their journey. This enigmatic human killed Martel. Mithos, driven mad with grief, misinterpreted her dying wish of a world free of discrimination believing it to be a wish for everyone to be the same. Mithos then established the order of Cruxis, with he, Kratos, and Yuan as its first angels. Since Kratos was human, and had no elven blood in his veins, unlike Mithos and Yuan, who were half-elves, he was forced to ingest a magical rock called Aionis, which allowed him to cast magic and use magical weapons, in order to become an angel. The companions became three of the Four Seraphim, with Martel being the fourth, ascended to Derris-Kharlan and founded the Church of Martel. They also founded the Desian organization, designed to aid Mithos in his plans.
After learning about Mithos' plans for the Age of Lifeless Beings, Kratos descended upon Sylvarant. There he met a human woman named Anna, a research subject in the Angelus Project, which attempted to culture a Cruxis Crystal within a human host. The two fell in love. Kratos soon realized that there had to be a better way to reunite the two worlds, and so he began to search for a way for a human to wield the Eternal Sword, the omnipotent weapon that Mithos had used to split the worlds. However, the pair was forever pursued by Cruxis, and soon they had a child, Lloyd.
Eventually, the Desian Grand Cardinal Kvar caught them, at which point Anna's Exsphere was removed. This caused her to become a mindless monster. She attacked the infant Lloyd, who was only saved when their pet Noishe interfered. These events caused Anna to temporarily regain her old self; she begged Kratos to kill her. He could not bring himself to do it, however, and Anna soon lost control again. She once again turned on Lloyd, and with Noishe too injured to help, Kratos killed her in desperation to save his son. Kvar then attacked, causing Lloyd, Noishe, and Anna to tumble down a cliff near the Iselia Human Ranch. Kratos managed to defeat Kvar and his men, and then descended the cliff, only to find ravaged Desian corpses. Believing his family to be dead, Kratos lost all meaning in his life. He soon returned to Cruxis, where he aided Mithos, believing that the half-elf would reunite the two worlds after Martel was revived.
When the Cruxis Crystal kept in Iselia's Martel Temple shines, Mithos sends Kratos to watch over Colette and make sure she does not stray from the Journey of Regeneration. He appears to Lloyd, Genis, and Colette as they battle a fierce warrior of a group the locals believe to be the Desians but are actually the Renegades: Vidarr. After defeating him, Kratos introduces himself as a mercenary, at which point Phaidra, Colette's grandmother, hires him to protect the Chosen. When the party travels to Dirk's house so Colette can speak to Lloyd, Kratos sees Anna's grave. It is at this point that he realizes that Lloyd is his son.
Once the party reaches the Tower of Salvation, Kratos goes on ahead of Lloyd and the others with Colette, delivering her to Cruxis. Lloyd and the others arrive just as Colette prepares to become a true angel, sacrificing her memory and her heart. Remiel reveals this to the party, and attacks them. The group manages to defeat him, and when Kratos reveals himself, Remiel begs for Kratos to save him. Kratos points out the irony that Remiel begs for help from a former human and allows him to die. Kratos then reveals himself as an angel of Cruxis. When Lloyd and the others learn this, they engage in a near impossible battle with Kratos. Afterwards, Yggdrasill himself comes to the tower and is about to kill the entire party before they are taken away by the Renegades.
Kratos is encountered once again in Tethe'alla, atop the Fooji Mountains when the party goes there to retrieve the Rheairds. During these events, the party becomes aware that there is some relation between Yuan, who they know only as the leader of the Renegades, and Kratos. Kratos is encountered by the party in Sybak as well. There he is even more mysterious, indicating that in order for Colette to live she must remove the Key Crest that cured her Angel Toxicosis, a request with which Colette does not comply. Throughout later events in the story, it becomes increasingly difficult for Lloyd and the others to understand his allegiance. Before the party severs the final mana link atop the Tower of Mana, Kratos appears and warns the party not to do so. However, after the Great Tree goes out of control and begins to tear the world apart, Kratos rejoins the party and aids them, against Mithos's orders, in destroying the tree.
Kratos appears before the group again as they attempt to enter Derris-Kharlan's city of angels, Welgaia, through the Tower of Salvation in order to gain a mana fragment to cure Colette's Chronic Angelus Crystallus Inofficium. It is here Kratos admits to them that he is one of Mithos's companions from 4,000 years ago, confirming what the elven storyteller had told them. Kratos engages the party in battle, at the end of which angels are summoned and ordered by Kratos to capture the party. The party also questions his motives, realizing that Kratos could have just led them all around Tethe'alla in order to get them to gather the supplies needed to save Colette. The next time Kratos encounters the party is when Yuan offers to let him meet Lloyd. At Altessa's House, Lloyd learns that Kratos is his father and immediately goes into denial. Yuan then threatens to kill Lloyd unless Kratos releases Origin's seal. Kratos seems impassive, but when Lloyd's attempt to attack Yuan fails, Kratos dashes in front of him to block what could have been a fatal blast from Yuan. Kratos falls unconscious, and Lloyd tries to get a grip on the situation. This is interrupted by a party member. Mithos makes an appearance directly afterward, revealing himself to be the leader of Cruxis.
In Flanoir, Zelos is seen talking to himself about Aionis- presumably after talking with Kratos. Kratos may appear once again, right after the Flanoir Doctor is escorted to Altessa's home. This is most likely if Lloyd refuses to go outside with anyone else. He will reveal to Lloyd all the events that transpired in Anna's death. Zelos later is seen speaking with Kratos after the doctor arrives at Altessa's house, and makes his decision to either betray the party while helping Kratos get Aionis, or to betray the party in order to die. Kratos next appears after the initial defeat of Yggdrasill in the Great Seed Chamber. He tells Lloyd that the only true way to reunite the two worlds is for him to wield the Eternal Sword. Kratos then proceeds to Heimdall's Torent Forest and waits for Lloyd at Origin's seal. After dueling Lloyd, Kratos is badly injured, but not killed, instead gaining Lloyd's forgiveness. Kratos then releases the remaining mana in his body and opens the seal to Origin, but Yuan appears and supplies Kratos with some of his own mana, saving him.
Salvation and BeyondEdit
Kratos gives Lloyd his Flamberge to use in conjunction with the Vorpal Sword given to him by Dirk. Combined, these make the Material Blade. Depending on the decision in Flanoir, Kratos may or may not join the party in the final fight against Mithos. If he does not, he will cite lingering weakness from the fight with Lloyd in Torent Forest. After the defeat of Mithos at the hand of Lloyd and the others, Kratos is one of the last angels remaining in the world. He agrees with Lloyd's idea that Exspheres should no longer be able to be used by people, due to the senseless waste of human life involved. For this reason, he decides to remain on Derris-Kharlan and scatter Cruxis's supply of Exspheres into space. He uses the remains of the Tower of Salvation to return to Derris-Kharlan, which now drifts into the depths of outer space.
Tales of Symphonia:Dawn of the New WorldEdit
Despite not being a playable character in Tales of Symphonia: Dawn of the New World, he maintains a very brief role during a cutscene that is accessible during the second and later playthroughs. During this event, Yuan talks to Kratos with a hologram communicator, stating that they have reached the limit of communication and must say their final farewell. Then Emil Castagnier and Tenebrae reveal themselves to Yuan and Kratos while they talk, and Yuan lets them speak with Kratos before the communication ends, briefly explaining to Emil who Kratos is. Also, much like in the first game, Kratos narrates the opening cutscene.
Kratos is displayed as a cold and heartless mercenary early in the game, though is also an expert in swordsmanship, a fact that makes Lloyd angry. The only thing he has in mind at the beginning of the game is to protect Colette, as that is what he is assigned to do. However, as the journey progresses, Kratos begins to open up a little, giving hints about a past where he made a terrible mistake. Throughout the early stages of the story, Kratos displays outstanding knowledge of the ancient world, raising Raine's suspicions. Despite his secret agenda, Kratos takes a keen interest in Lloyd's development as a warrior, although he takes a fairly callous approach to this. Through a sidequest, Kratos will train him in swordsmanship and give him advice that helps the young boy to grow. Despite his long life and many years of experience, Kratos is, up until the end of the story, a fatalist. For much of the story, he believes that Mithos's is the only way. This changes if the player triggers the scene with Kratos at Flanoir. It is Lloyd's actions that make him realize how much control of his destiny he really has.
Story of Joining Sora's TeamEdit
When Kratos was fighting Subspacers, and Castlevenoms, he soon spotted Riku, Yu Kanda, and Bugs Bunny fighting a Wargoyle. After they won, Kratos appeared to ask them to join in on the fun. After Sora sent a message to the others, Riku, Yu Kanda, and Bugs, with Kratos, rushed to where the Keyhole was located in. When everyone met up, and Sora used his Keyblade to open the new pathway. Soon after Lloyd joined, Kratos joined with his friends.