Lord Marshal Vladimir Krell alone holds the rank to bear the marks of leadership upon his knight armour. As the master of House Rajha he rules with absolute authority and he is a lord of death among a house of killers. He leads his banner with all the fervor of a madman and can be as deadly to his own men as the enemy. Some believe he was a follower of the Blood God before His worship was spread by the Heresy. Like all who follow Horus into rebellion Krell bears the Great Eye of the Warmaster to the worlds he devastates.
House Rajha is mentioned in Horus Heresy book 3: Extermination as a knight house that is allied with Legion Fureans. All that is said about them is that they are "ghost-grey". So naturally I decided to make up my own color scheme and background.