Mor Deythan - History: Corvus Corax was separated from his father the Emperor of Mankind while still an infant in the Emperor's gene-laboratory beneath the Himalazian (Himalayan) Mountains on Terra by the machinations of the Ruinous Powers of Chaos. The Chaos Gods snatched the infant Primarch's gestation chamber and flung it through the Warp half-way across the galaxy. Corax was eventually discovered on the world of Lycaeus, the desolate but inhabitable moon of the planet Kiavahr. At this time, Kiavahr was a technologically advanced Forge World, providing its city-size manufactoria with minerals extracted from the non-atmospheric moon by legions of mine slaves, and was home to a guild of Tech-masters who were open in their hatred towards the Mechanicum. Under the iron watch of heavily-armed guards, the enslaved inhabitants of Lycaeus, who included criminals, political opponents and workers who had failed to meet their quotas, had long provided the rulers of Kiavahr with a free and unlimited source of manpower. When they discovered the pale-skinned child who became Corax, "The Deliverer" in the Kiavahran tongue, they kept him from their masters, training him in the various skills they believed a leader and warrior needed. Educated to be a leader of men as well as a rebel guerrilla, Corax began his task by organising the Lycaean workers into fight teams, promoting the best to squad leaders. The first Mor Deythan were formed from the best warriors who followed Corax during his shadow crusade to free the moon of Lyceaus from the rule of the Kiavahran Tech-masters. Corax fought a hard and bloody guerrilla war against these tyrants, and afterwards, when the Emperor came to the newly renamed moon of Deliverance, those young enough to withstand the augmentations became the first Space Marines of the XIXth Legion.Amongst the ranks of the first Deliverance-born Astartes were those who displayed the same unique ability as their Primarch, enabling them to "Shadow-Walk". Through some genetic quirk of their gene-seed, a small percentage of these Astartes had inherited more of their Primarch's genome than any of their Terran-born brethren. Forming a specialised unit known as the Mor Deythan, Corax utilised his formidable knowledge of stealth and sabotage to the fullest extent, training these specially selected Legionaries to be called upon to perform highly dangerous reconnaissance and guerrilla missions deep behind enemy lines. Nicknamed "Shadow Masters", this elite unit was not known even amongst the members of their own Legion. Only the Primarch himself and a select group of Legion Apothecaries were aware of the Mor Deythan at the time of the Horus Heresy. Often times Corax would call upon the Mor Deythan to test highly temperamental thermal technology to help further their goals and objectives against their enemies.By the time of the Drop Site Massacre of Istvaan V, the Mor Deythan were few in number, having fought countless campaigns over eight standard decades at their master's side and they rarely admitted new recruits into their ranks. During this time, many of their number were too spread out across the galaxy performing their missions when the deadly events of Istvaan V transpired. After carrying out countless missions on behalf of their Primarch, attrition began to take a serious toll on their numbers. Most who remained were grizzled veterans, supremely confident in their abilities. They were adept at moving silent and unseen through the shadows and attacking as and where they willed. They utilised a range of weapons and specialised equipment, but there were some that whispered that the Mor Deythan were possessed of a portion of the preternatural skills of their gene-father, the Primarch Corax, including his ability to walk unseen even in full view of the foe. This ability had somehow been passed on to them through the unknowable processes of gene-seed implantation. Following the bloody events of Istvaan V, in which a large proportion of the Raven Guard Legion were lost, only a few dozen Mor Deythan were left alive. These few specialised elite warriors continued to fight on against the treachery of the Warmaster Horus and his Traitor Legions until the last of their numbers finally fell in service to the Emperor. It is not known if the Mor Deythan still exist as part of the Raven Guard Chapter in the late 41st Millennium.