Angels Revenant - Orphean War: In 990.M41, the violent Warp turbulence that had held sway across the western division of the Orpheus Sector for more than three standard centuries was rapidly and suddenly extinguished by a shockwave in the Immaterium, leaving only the Howling Vortex Warp rift remaining.All across the sector, astropaths, psykers and witches were subjected to sudden and inexplicable deaths or were hopelessly mind-burned. Reports of mass-hysteria, unexplained murders, disappearances and mania increased exponentially across the worlds of the Cold Veil and the Drucillan Sub-sector.The Ordo Malleus of the Inquisition's Conclave Orpheus, based on the world of Apollyon, issued an order for maximum vigilance to all Imperial authorities, believing the Warp disturbance and its attendant phenomena were but a precursor to a major incursion into the sector.Within a standard year, Astropaths reeled against a tangled, overlapping cacophony of telepathic distress calls and the echoing of psychic screams of the dying, distorted to near incomprehensibility and folded in overlapping time. Riding on this tide were other, far stranger, calls; blazing pillars of energy spiking into the Aether on the edge of the Veiled Region.Pulsing like beacons these fountainheads of power spilled off howling gales of radiation and charged particle storms that seemed free to transcend the gulfs of distance between stars in mere moments. These flaring storms of energy danced like static discharge along Warp routes and clung in ghostly cold fire to the hulls of starships.The seething electromagnetic contagion they brought with them whispered in unknown tongues that invaded vox channels and supposedly sealed and secure communications webs, the fading echoes of agonised screams following in their wake.With it one phrase in Imperial Low Gothic repeated again and again: "Maynarkh comes." Havoc followed wherever the malign signal went, as machinery was plagued with sudden failure and malfunction, servitors were driven mad and cogitators were locked in terminal loops, their Machine Spirits shocked into stuttering apoplexy.Yet at this time the true nature of the threat remained unknown. Imperial authorities had no definite evidence as to the face of the enemy, which remained hidden. Astropathic messages sent towards the edgeward worlds were swallowed up unanswered, while any vessel that attempted to pass a line of darkness that stretched across the sector in a curving scimitar-like arc from Tlaloc to Epirus simply did not return.Perhaps most disquieting of all was the silence of Libethra, the Chapter homeworld of the Angels Revenant Chapter, who had long served as the sector's stalwart defenders and most powerful of warriors. For Libethra also to be struck silent by this mysterious doom sent a splinter of cold panic into the hearts of the Orphean Imperial Commanders that they dared not acknowledge.But it was this factor more than any other that threw them into a policy of panicked preparatory defence rather than responding with blind counter-aggression as they might have.Of the final fate of the Angels Revenant Space Marine Chapter, little can be said for sure. Libethra, where a hundred basilicas had been raised to honour the blessed dead and where the Angels Revenant Chapter had served as sentinels for the entire sector, was now a black sea of shifting ash, riven by lurid red lava -- all traces of the Imperium's hand obliterated.Such scattered and fragmentary evidence that has been uncovered about their final hour suggest unsurprisingly that they fought to the last against the overwhelming forces unleashed against them, as the Libethra System was found littered with the radiation-ghosts of deadly void combat and spreading clouds of micro-wreckage.Furthermore, the ancient hull of at least one of the vast Necron Tomb Ships that were later sighted above the world of Amarah during the Orphean War against the Necrons of the Maynarkh Dynasty held fresh scars consistent with the unique signature of Space Marine bombardment cannon strikes at extreme close range.Indeed it may be the case that such was the resistance the Angels Revenant put up that the Necron invaders resorted to breaking through Libethra's crust and unleashing the planet's molten core to seal their fate conclusively. When news of the Chapter's martyrdom reached the Ecclesiarchy's Synod Tempestus, a Segmentum-wide day of requiem was decreed, the bells of a thousand worlds across the Segmentum Tempestus tolling to mark the passing of the Angels Revenant.It was thought that no more than a few hundred Angels Revenant survived, and only those who were away from their Chapter homeworld on crusade when the Necron assault came upon Libethra.