Today I will finish my ranking of the Primarchs.
5. Leman Russ, Primarch of the Space Wolves
Anyway, Russ is considered by many of his brother Primarchs to be just like Angron, that he is nothing more than a blood mad killer. He surely is that, but unlike his brother Angron he is playing the role that is asked of him. He does not complain about what the Emperor asks of him, he merely does what is asked.
Russ is also very thoughtful and introspective in a way few would ever expect. He is quite possibly the most self aware of all the Primarchs.
Like so many of his brothers, Russ grew up on a world that was not pleasant but rather than give in to despair he adapted to his surroundings and survived.
Russ is also one of, if not the most amusing of the Primarchs to read about.
4. Rogal Dorn, Primarch of the Imperial Fists.
Rogal Dorn among all the Primarchs believed in his father's dream of a unified galaxy. He was not his father's favorite son and yet when Horus falls and declares his allegiance to the chaos gods the Emperor turns to Dorn to fortify his realm and Dorn does so without comment.
Rogal Dorn turns the Imperial Palace, the most architecturally magnificent structure in the galaxy, into a fortress. Unlike Perturabo who would smash beauty into pieces for functionality, Dorn is pained by each masterpiece that he has to wreck.
Moreover, as news comes of each of the Primarchs that have turned away from the Emperor; Dorn is tormented by this news. He does not know their individual reasons why and yet he wants to give them the benefit of the doubt. He wants to try to understand. That his brothers are lost to him haunts him for the remainder of his life. Dorn is one of the tragic Primarchs.
3. Sanguinius, Primarch of the Blood Angels
In many ways Sangiunius is parallel to Fulgrim. Both are artistic and highly skilled in areas beyond warfare such as music, poetry, and art. The difference is that Sanguinius does these to honor his father the Emperor, Fulgrim did if for his own aggrandizement.
Sangiunius did have his flaws, one of which plagues his Chapter to the current Millenium. However, unlike some of his brother Primarchs, whose flaws they either flaunted or sulked about, Sangiunius still continued to do his best to further his father's vision.
Most telling about Sangiunius' character is the fact that he had the gift of foresight. He knew that he was going to his death when he boarded the Vengeful Spirit to battle Horus. He went anyway, he sacrificed himself to allow the Emperor to be able to defeat the Arch Traitor.
Sacrifice, magnanimity, artistry in all forms make Sangiunius one of the best Primarchs.
2. Robute Guilliman, Primarch of the Ultramarines
While other legions focused on conquest, Guilliman focused on building the foundation of the Imperium. He made sure that every planet that he brought into the Imperium was self sufficient, able to feed itself, provide for its self defense and more. Some of his more war loving brothers laughed at this, but Guilliman also conquered more worlds than all of his brothers save Horus.
Guilliman was not able to be present for the Siege of Terra, for which he never forgave himself, but he and his Ultramarines were responsible for pushing the traitors back and keeping the Imperium together right after the Heresy ended.
If the above wasn't enough to secure his place so high on this list, then let us not forget that the Realm of Ultramar, the Ultramarines home worlds, are the only worlds of the Imperium relatively free from the uber fascist government. Ultramar is a beacon of hope against the darkness of the 41st millennium.
1. Horus Lupercal, Primarch of the Luna Wolves, later the Son's of Horus
That has changed. Horus has been re-imagined to show why he was the Emperor's favored son, that before his fall he was the best of his brothers.
Horus was a diplomat supreme
He possessed wisdom without equal
A Warrior without equal
A general that all the Emperor's enemies feared
Above all, Horus was patient and benevolent, always offering the olive branch of peace before unleashing his Luna Wolves in war.
That he was so great makes his fall from grace all the more sad. No one would be surprised that Night Haunter or Angron would turn, both being so damaged by the world on which they were raised. Nor would anyone be shocked that Primarchs with obvious character flaws like Lorgar could be turned.
Horus was none of those, thus Horus secures his place as the greatest son and most feared enemy of the Emperor.