Mortarion - Cicatrix Maledictum: Abaddon the Despoiler united the disparate factions of the Eye of Terror and unleashed the 13th Black Crusade to bring ruin to the world that had proven his nemesis for millennia. The Fortress World of Cadia, which had long stood sentinel over the Cadian Gate, finally fell to the Despoiler during that campaign. The destruction of Cadia eliminated the mysterious geometric pylons that dotted the Fortress World's wind-swept outlands, and in doing so weakened the barrier between worlds, for these ancient megaliths were fashioned to keep power of the Warp from overwhelming the material dimension.The Despoiler's agents repeated the same act on every world that harboured similar structures. Without these lynchpins to hold the material dimension sacrosanct, the Materium could take no more, and a titanic Warp rift tore across the galaxy, spreading from the Eye of Terror to the Hadex Anomaly on the Eastern Fringe. To those on the Terran side of the so-called Great Rift (or the Cicatrix Maledictum in High Gothic) it is a tainted scar stretching across the sky. To those unfortunates on the far side, in the region now named the Imperium Nihilus, the "Dark Imperium," it is something much worse -- the very gates of Hell.Though the Imperium now faced its darkest hour, all was not lost. A valiant band known as the Ynnari, a mixed faction of Aeldari and Drukhari in service to their awakened God of the Dead Ynnead, followed a radical path that they believed would see Chaos defeated and the Aeldari race resurgent. Compelled by fate or circumstance, the Ynnari lent their aid to Archmagos Belisarius Cawl, Saint Celestine and Inquisitor Katarinya Greyfax and rescued them from the forces of Abaddon on Klaisus, the ice moon of Kasr Holn after the fall of Cadia.Together, the Ynnari and their newfound Imperial allies forged a path through their foes and the Webway to Ultramar. Upon Macragge, the Chapter homeworld of the Ultramarines, a miracle was wrought within the Fortress of Hera through the technological prowess of Belisarius Cawl and the power of Ynnead as embodied in his priestess Yvraine, the Daughter of Shade. Roboute Guilliman, Primarch of the Ultramarines who had been trapped for 10,000 standard years in stasis, was restored to the realm of Mankind.Deep within the noisome swamps of Nurgle's Garden in the Realm of Chaos, a conclave of Great Unclean Ones listened indulgently to the frantic babbling of messenger flies. They leered in delight, bile and maggots slopping down their festering chins. A Primarch! One untouched and untainted by any of Nurgle's brothers. Their pestilential master would no doubt value such a prize most highly. Perhaps, they chortled mockingly, they might even arrange a final reconciliation between the bitter Mortarion and his brother. Such an opportunity had not presented itself in thousands of years, and the Great Unclean Ones hummed a cheerful ditty as they began to concoct a sickness fit for a demigod.Upon a far-fung hell world, Mortarion received word of his brother's awakening. Mortarion raged, a cold and virulent storm of anger whirling around him until its echoes in realspace seeded seven new and terrible plagues upon luckless Imperial worlds. Mired amid plans that were nearing fruition, the Daemon Primarch of the Death Guard could not yet act to strike at Guilliman. Instead, as he stared with glowing eyes across the mist-wreathed parade grounds of his Plague Planet, and the massed ranks of Death Guard there assembled, Mortarion vowed that he would render Guilliman and his empire to rot soon enough.