The Khadidas was a demon utterly loyal to Kina, and a dangerous enemy of the Black Company during Soldiers Live, the final Book of Glittering Stone. The evil entity possessed the body of Goblin, the elderly Company wizard, and worked relentlessly to bring about the Year of the Skulls.
The Khadidas resided inside Kina's body for millennia, trapped with her in their prison beneath the fortress with no name, at the center of the glittering plain. At the end of Water Sleeps, the old wizard Goblin entered Kina's chamber with the Lance of Passion. The demon exited Kina's body through her nostril in the form of a wisp of menacing blue flame, and took possession of Goblin's body. Goblin was presumed dead, and was left behind by Sleepy, Tobo, Suvrin, and Master Santaraksita, who realized that he sacrificed himself to save them all.
In Soldiers Live, Blade discovered that Goblin had apparently survived the harrowing encounter. However, this was actually the Khadidas in possession of the elderly wizard's body, with the true Goblin's ghost trapped, asleep, within his own flesh. The Khadidas kept the Company in the dark about his true nature until his eventual escape.
Sleepy was deeply distrustful of Goblin after his rediscovery, so she sent him off to the Voroshk world accompanied by the Chun brothers under guard. There, Lady was convinced he somehow assisted her, Croaker, and their group in bringing down the forvalaka Lisa Daele Bowalk, an old Company nemesis. He left with this group, trusted by none, when they departed the Plain and entered into the homeworld. At some point, he secretly put the Voroshk teenager named Sedvod into a cursed coma which eventually killed him.
Then, after the Company captured Nijha, the Khadidas quietly approached Narayan Singh, the Company's captive and the best of the Stranglers. Speaking in Deceiver's Cant, the Khadidas assured Narayan that he was Kina's favorite servant throughout all history. He then quietly granted Narayan a holy death with a rumel. He then escaped the Company to go and replace Narayan as the guardian of the Daughter of Night, Kina's messiah.
The Khadidas, utterly fixated on the task of rewriting the Books of the Dead, caught up with the Daughter of Night. Not long after, they were both captured by the Protectorate forces of Soulcatcher, the Daughter's maternal aunt. Soulcatcher slashed the Khadidas's eyes, blinding him, but only temporarily: with a portion of Kina's immense powers within him, his eyeballs soon regenerated. He and the Daughter were kept in separate cages within Soulcatcher's command tent. In the midst of the Battle of the Middle Ground, while Soulcatcher was carefully managing her battlefield sorcery from a distance, the Khadidas made his move. He hit Soulcatcher with a spell that functioned like a curse, putting her into an irreversible, coma-like state. He and the Daughter then took command of much of Soulcatcher's Middle Army, but they were soundly defeated by the Black Company. The two fled to the Grove of Doom.
In the Grove, he was a strict guardian and the Daughter disliked him in comparison to her years with Narayan. Though they had no writing materials at the Grove with which to write the Books of the Dead, he ceaselessly instructed her in the philosophy of her role. During the Battle at the Shadowlander cemetery, they were both suddenly subdued and captured by Mogaba's general, Aridatha Singh, and were sent under heavy guard to be imprisoned within the Palace of Taglios. They escaped into one of the abandoned sections of the sprawling Palace, using sorcery to remain hidden, and feverishly began rewriting the Books of the Dead. They were captured by Tobo in the aftermath of the Siege of Taglios. The Khadidas, in a last ditch effort, used a deadly spell, but it bounced off Tobo, who was an experienced sorcerer and heavily-protected. However the spell ricocheted and struck the Prahbrindrah Drah, killing the rightful ruler of the city.
Later, Croaker forced the entity into submission by gluing One-Eye's hat over Goblin's head and securing One-Eye's spear into his hands. This restored the true Goblin, although the old wizard was merely a shadow of his former self. The Khadidas was obliterated when, as Goblin pierced Kina's skull with the spear, Croaker detonated Goblin's rheitgeistiden in her chamber.