After the opening of the Great Rift in the late 41st Millennium House Khymere was corrupted to the service of Chaos when its homeworld was unexpectedly attacked by a force of the Indomitus Crusade, whose Space Marines claimed Chaos-corrupted House Khymere Knights had been attacking Imperial worlds.
Unwilling to make war against the Imperium they had so long defended, the entire house fled into the Warp Storms of the Great Rift. Their exposure to the empyrean energies of the Warp corrupted many of the Khymere Knights, who returned to realspace filled with hatred for those they felt had betrayed them.
Unknown to the Chaos Knights, their travels in the Warp had also displaced them in time. The Renegade Knights had been thrust into their own past, unleashing the very attacks that had led to the Imperial assault that resulted in their damnation.
The Khymere homeworld of Surtr's Wake is a desolate graveyard, lined with crumbling statues built by the Nobles of House Khymere and littered with the remains of felled Knights. Since their exodus, the Iconoclast household that once called this lost world their home have not returned.
For ten thousand Terran years the Knights of House Khymere had fought ferociously for the glory of the Imperium of Man. The cracked and burning surface of Surtr's Wake was dotted with monolithic statues of the Emperor, towards which the faithful serf classes of the planet prayed for solar hours every day.
Many times did the Nobles answer the summons to join a gathering Imperial Crusade, and when desperate pleas for aid came from nearby star systems, the Knights of Khymere marched with burning wrath against the enemies of Mankind.
Yet when the Cicatrix Maledictum tore across the stars, the Knights of House Khymere were amongst the nightmarish warriors who burst from the Great Rift to prey upon the worlds of the Imperium. Many of these once-valiant war engines were hideously twisted, the corruption that had evidently taken hold of them expressed in their grotesque forms and rampant cruelty.
In an edict that caused great anguish to those they had once served, the Knights of House Khymere were declared Iconoclast, and Surtr's Wake -- now shrouded within the Imperium Nihilus -- was marked for destruction.
When the Indomitus Crusade reached Surtr's Wake, Adeptus Astartes strike forces of the Ultramarines and White Scars Chapters were tasked with launching an execution assault against the planet. But the warriors of House Khymere offered no resistance to the Imperial attack; the nobility -- seemingly untouched by Chaos taint -- could not fathom that they had been deemed Traitors, nor could they bring themselves to raise their weapons against those to whom they had sworn loyalty.
Instead, the entire house withdrew from the planet. They marched their Knights onto vast fleets of mass conveyance barges and fled from judgement by disappearing into the roiling tumult of the Great Rift. In truth, the house was displaced through time during its sojourn in the Empyrean, its Knights returning to realspace in their own past.
Lances of Khymere Knights continue to burst into reality along the length of the Great Rift. Where they appear, their wrath is quickly turned upon the defenders of the Imperium. Attempts to treat with them have been met with silence or maddened ramblings, for what nobility once existed in the house is now long gone.
Conflagration of Rho Zapphire
Above the gas giant of Rho Zapphire, a strike force from the White Scars 6th Company fought a war of speed against an invading host of Slaaneshi daemons soon after the opening of the Great Rift. The Space Marines raced to secure the vital aether-derricks that are suspended in the planet's thermosphere, cutting their way through screaming droves of Daemonettes and Fiends of Slaanesh that skittered along the equatorial gantries, even as more depraved beings pour from the nearby maw of the Great Rift.
The fuel from these derricks was crucial for the Imperial fleets withdrawing from the encroaching Warp Storms of the newborn Great Rift, but the daemons outnumbered the White Scars a hundred times over. The battle appeared to take a shift when a flotilla of macro-conveyance barges swooped into low orbit and disgorged its cargo of Knights.
But the hope of reinforcements was short-lived. The Chaos Knights of House Khymere that marched onto the floating gantries opened fire on the Space Marines, obliterating those few that remained.
When cruisers from the Imperial Navy arrived to refuel, the Chaos Knights departed, but not before overloading the core of each aether-derrick. The ensuing chain reactions ignited the volatile atmosphere of Rho Zapphire, incinerating the refuelling fleets as the entire planet exploded.
- Burning Sky - The Burning Sky is a Knight Rampager piloted by Lady Brinhild.
- Mantle of Ashe - The Mantle of Ashe is a War Dog piloted by the Fallen Noble Gelki.
- Scorched Fury - The Scorched Fury is a War Dog piloted by Uthren.
- Lady Brinhild - Brynhild was present on Surtr's Wake when the Space Marines attacked without warning. With the rest of her house she had fled into the Cicatrix Maledictum rather than face the shame of fighting those to whom she had sworn loyalty. But after passing into the mass of Warp Storms, time lost all meaning. For an indeterminable period of time, Brynhild and her Knight, the Burning Sky, fought an endless deluge of nameless, faceless entities wrought of madness and nightmare. Within her own mind she heard the constant screams of her forebears contained inside her Throne Mechanicum, tortured as they were by the overload of empyric energy. With every Chaos being she cut down, her hatred grew further. Eventually, all that remained in both pilot and Knight was a desire for revenge against those they had once served. When at last they emerged from the Warp, they set themselves to their murderous task, completely unaware that they and the remainder of their house had been displaced in time by the Great Rift, and sent back into the past to initiate the cause of their own corruption.
- Gelki - Like most War Dogs of Khymere, Mantle of Ash and its pilot, Gelki, willingly accept their position as subservient thralls, so long as they are driven by their masters to slaughter the Adeptus Astartes Chapters that attacked their house.
- Uthren - Time and again Uthren and his War Dog Scorched Fury have demonstrated their remarkable resilience. They are frequently sent charging through raging firestorms or fields of acidic geysers to attack from the angle their enemies least expect.
House Khymere's Knights sport red and black house colours with brass trim.
The heraldry of House Khymere is a black horse which breathes yellow fire.
- Codex: Chaos Knights (8th Edition), pp. 18-19, 29, 32-33