He is a master of magic, able to transform foes with boons of mutating flesh, turning them into tentacle-ridden Chaos Spawn, or incinerate them with multicoloured blasts of fire. He carries the Staff of Tomorrow into battle. Since Kairos had been thrown into the Well of Eternity by Tzeentch his personality is split into two different heads. The right head can see the future clearly, and the left head sees the past, but both heads are blind to see the present. 
During the Age of Chaos and the early part of the Age of Sigmar he acted as an untrustworthy and mocking patron to the sorcerer Ephryx the Ninth Disciple of Tzeentch. He intended for him to enact a ritual that would move the entire Realm of Chamon into the Realm of Chaos and bring it under the direct control of his master and god. However he lost control of Ephryx who struck him down with a Staff of Change, incapacitating him long enough for Vandus Hammerhand to claim Ghal Maraz and destroy the physical form of the Greater Daemon.
At the head of a large army of demons of Tzeentch, he laid siege to the heavenly sky-port of Barak-Zon for 99 days. The defenders held out long enough for a fleet of major sky-ports to arrive under the command of Brokk Grungsson and repel Kairo's band of demons.
- 1: Battletome: Disciples of Tzeentch (2017)
- 2: Kairos Fateweaver product description
- 3: Kairos Fateweaver warscroll
- 4: Call of Chaos: The Crystal of Fate
- 5: The Eldritch Fortress (novel) by Guy Haley
- 6: Battletome: Disciples of Tzeentch (2020) - Kairos Fateweaver, p.30
- 7: Battletome: Kharadron Overlords (2017) - A Rising Power, p.26-27
- 8: Battletome: Kharadron Overlords (2020) - Annals of the Overlords, p.20-21