Kairos Fateweaver - Horus Heresy: In the last century of the 30th Millennium, four solar decades before the start of the great galactic civil war of the Horus Heresy, Kairos Fateweaver appeared to the Primarch of the Word Bearers Legion, Lorgar Aurelian, during his infamous Pilgrimage into the Eye of Terror.The Fateweaver offered Lorgar a choice that would ultimately change the shape of the galaxy's history. Using his precognitive vision of the future, Kairos explained that Lorgar could seek revenge upon his fellow Primarch Roboute Guilliman for his shame at Monarchia on the world of Khur where the Emperor had humiliated the Word Bearers for failing to uphold the Imperial Truth. But this action would doom the chances of Chaos for overthrowing the Imperium of Man in the conflict to come.Or he could put aside this petty search for satisfaction and choose to serve the broader cause of Chaos, perhaps ensuring the victory of the Chaos Gods over the Emperor of Mankind and the union of humanity and the Primordial Annihilator. This is the only known instance where both of Kairos' heads told the same truth, so important was this choice to Tzeentch and his fellow Ruinous Powers.After the Heresy had begun, Kairos once engaged in battle with the primarch of the Dark Angels Legion, Lion El'Jonson, aboard his flagship, the Gloriana-class Battleship Invincible Reason. The Invincible Reason had been thrust unexpectedly into the Warp without being able to raise its Gellar Field following a battle with a Night Lords Legion Eclipse-class Light Cruiser, the Avenging Shadow, several solar months after the battle between the Lion and his brother Primarch Konrad Curze at Tsagualsa during the Thramas Crusade.A horde of Tzeentchian Daemons assaulted the vessel, including Kairos, who inadvertently revealed during a telepathic conversation with the Lion that the Emperor was still alive. The Lion managed to distract the Daemon and stab one of its heads with his blade Despair, banishing it back to the Warp. Before Kairos fully dematerialised, the Lion sarcastically asked him whether he had seen that coming. Eventually, the Invincible Reason was able to stabilise itself fully within the Warp, brings its Gellar Field back up and continue on its journey despite the deaths of 300 Astartes and 600 Chapter Serfs.At some point after the fall of Prospero, Kairos was found by the Thousand Sons bound into a device known as the Iron Oculus. The Thousand Sons primarch, Magnus the Red, ordered the Oculus to be brought into possession, and Ahzek Ahriman was successful in retrieving it from the race of mechanical beings called the Yokai.Fateweaver was then transferred from the Oculus and placed into a Yokai named Aforgomon who aided Ahriman in recovering the Shards of Magnus, the portions of Magnus the Red's psyche that had been spread across the galaxy during his attempt to breach the psychic wards of the Imperial Palace and warn the Emperor of Horus' betrayal before the Heresy began. During his time with Ahriman's Cabal, Aforgomon was able to manipulate Hathor Maat, desperate for salvation from the Thousand Sons' rapid mutational flesh change, into changing a single line of the Book of Magnus.On Nikaea, Aforgomon was finally able to manifest into his proper form as Kairos through Hathor Maat due to a pact made with Ahriman. After manifesting, Kairos aided Ahriman in confronting the Shard of Magnus, and Magnus revealed that the Daemon was known as "The One Who Comes at the Appointed Time" before trapping it with his psychic powers.When Ahriman found the Shard of Magnus to be too powerful, the Thousand Sons Sorcerer demanded more power, which the Daemon gave to him, and Ahriman was able to merge with a portion of Magnus to battle the Shard before he released the daemon. After the Shards of Magnus merged, Kairos transported the Thousand Sons back to the Planet of the Sorcerers and then vanished back into the Warp.