Malcador the Sigillite
Malcador the Sigillite (Also known as Malcador the Hero, Malcador the Mary Sue and Malcador the Laundryman Of Teh Emprah) was Regent of Terra, Master of the Administratum, Grand Master of the Officio Assassinorum, and all around bestest bud of the Emperor of Mankind during the Great Crusade and the Horus Heresy.
History
Having served the Emprah during the unification of Terra (meaning he was fucking OLD for a human), he was present during the creation of the Primarchs and advised the Emperor during the early crusade. When the Primarch's started getting collected and the new Imperium spreading outwards, Malcador remained as Regent of Terra, acting as a prime minister who kept the day-to-day activities of Imperium of Man running, sponsoring various agencies (like the Remembrancer Order), appointing the Council of Terra and building the Administratum from the ground up.
After the Emperor returned to Terra and set up the Council of Terra, the Emperor appointed Malcador to the position of First Lord of the Council (essentially the civilian ruler of the Imperium at that point, where the Warmaster was the military commander) while the Emperor descended into the Imperial palace and set to work on building the Webway.
When the Horus Heresy broke out, Malcador worked closely with Rogal Dorn in preparing the defenses of Terra and co-ordinating the logistics of the war-effort, as well as overseeing a formation of special projects such as the Adeptus Astronomican (who were required to replace the Emperor in powering the psychic beacon), the Officio Assassinorum and towards the end of the Horus Heresy; the formation of the Grey Knights.
He is dead. Very, very dead. During the Siege of Terra, The only chance that the Emperor could get to join the battle would be if someone took his place sitting in the Golden Throne (since Magnus broke it and threatened Terra with a new Eye of Terror) Malcador's psychic power meant he was the only potential candidate to take the Golden Throne while the Emperor fought off the Chaos Space Marines. However, since he wasn't a psyker of equivalent level to the Emperor, the process wore him out and he crumbled to dust after the Emperor was returned to the seat by Rogal Dorn and Jaghatai Khan. With his last ounce of strength, he allowed the Emperor to communicate with his mortal servants one last time. Truly, an all around awesome bureaucrat.
Mission
There was much more to Malcador than meets the eye. He claims that he is part of a very old order that has guided humanity from the very beginning, and that the =I= symbol often associated with the later Inquisition was actually the symbol of his order, therefore he was probably one of the old-school Illuminati.
He also does not see eye-to-eye with the Emperor either, disagreeing on some very fundamental points: Malcador worried about the Emperor being so far above humanity, so inspirational that his efforts to squeeze out superstition and religion would eventually because cause religious cults would form around himself and his sons instead, which is exactly what happened.
He also warned that humanity would be so invested in the Emperor that if he were to ever leave or die, humanity would not be able to handle the shock and would be left paralysed and defenseless. Though the Emperor himself dismissed this as nonsense, since his intention was to raise humanity and allow it to think for itself - Yet another miscalculation on his part.
Therefore it could be said that all of Malcador's efforts to create agencies the Imperium would need later were all part of an insurance policy that humanity could deploy if it ever turned out that the Emperor and his Primarchs could not be relied upon to carry humanity on their shoulders.
Credits
He was the third most powerful human psyker of his time (after Big E and Magnus the Red), being able to do things such as plunging the entire moon of Titan in the Warp to protect what would become the Grey Knights from the attacking Traitor Legions.
Though it has never been seen, he must have been one badass warrior too, since he was the Grand Master of the Assassins.
He proposed the Chaplain edict, ironically taking the idea from Lorgar and Sanguinius though back then they were more like Commissars, keeping order and looking for heresy, instead of the modern day warrior-priests.
There is also a tank named after him, though nowadays another tank named after an important hero and leader of the Imperium is used instead, the Leman Russ, passing over yet another perfectly servicable vehicle. Russ is a glory hogger like that.
He was also potentially the busiest man in existence, having founded pretty much the ENTIRE Imperium single-handedly. The organizations he founded--the Administratum, the Officio Assassinorum, Adeptus Astronomica and the Inquisition--have been fucking up everything else and each other ever since without his guidance.
His force staff has also passed into the hands of Varro Tigurius, because Ultramarines.
