Mor Deythan

The Mor Deythan was an elite unit type of the Raven Guard Legion. Created by the Primarch Corvus Corax, the Mor Deuthan were used as elite recon troops or scouts. They utilised Chainswords and Bolt Pistol  as base but often ddeployed Sniper Rifles, Shotguns or other rare weaponary such as Volkite Chargers. Nicknamed "hadow Masters", these elite Legionaires were rumored to have been granted an extra skill that allowed them to walk in plane sight invisible.

History
The first Mor Deythan were formed from the warriors whol followed Corvus Corax during his shadow crusade to free the moon of Lyceaus, now known as Deliverance, which orbited the fallen forge world of Kiavarh. Kiavarh was home to a guild of Tech masters who were open in there hatred towards the Mechanicum. Corax fought a hard and bloody guerilla war against these tyrants and afterwards, when the Emperor came to the now named Deliverance, those young enough to withstand the augmentations became the first Space Marines of the Legion.

As the XIX legion entered the Great Crusade, Corax used his knowledge of stealth and sabotage to full extent, often calling upon those few Legionaires who had already fought under his command in the freeing of Deliverance to perform these tasks. Over the countless missions, these Astarte's formed an elite unit known as the Mor Deythan who specialised in high risk reconnaisance missions.

By the time of the Drop Site Massacre, very few Mor Deythan were left alived. After countless missions there numbers had begun to dwindle. After the bloody battle in which nearly all of the Raven Guard were lost, only a few douzen Mor Deythan were left alive. Although these few continued to fight until the last of their numbers had finally in service of the Emperor.

Although not clearly stated, it is highly unlikely that the Mor Deythan still exist in the 41st millenium for no Legionaire who fought with Corax on Deliverance are left alive. However it is possible that the last Mor Deythan passed on there skills to there future succesors.