The Palatine Phoenix is a novel as ambitious as its protagonist.
To summarise: Fulgrim seeks to conquer a world with only seven warriors accompanying him. Even for a primarch, that's pushing things. What this leads to is a wonderfully minimalist narrative that plays to Reynolds' strengths; where world-building, character and intrigue play far more of a part that out and out warfare.
What really drives this narrative is Fulgrim's feelings of inadequacy. Only ruling one world when found, he's thrust into a galaxy where primarchs found since have had more holdings to begin with. His own Legion's struggles with the geneblight that almost destroyed them has left its mark, with him constantly considering the "what ifs" had he been present. It's a small part of the background refrain, but it affects enough of the characters to flavour the story as it progresses.
Fulgrim wants to show himself as capable of not only standing on his own two feet, outside of Horus' shadow, but also of being better than the "blood and fire" attitudes his brothers hold towards the progress of the Crusade. He seems particularly incensed by Russ, whose jibes have made him strike out alone sooner than some expected.
The warriors he brings with him are a mix of old and new. As a huge fan of the Katara Xenocide aside in the FW background on the Emperor's Children, it was a joy to see Lord Commander Abdemon brought to life (NB: Please let Josh write a Katara Xenocide story). He's a stern but fair commander, personable if comparatively blunt; considering war his art and so sitting aside from the more cultured norm of the Third. He's by no means stupid, nor bland, nor one dimensional, but instead is compelling in his presentation.
Narvo Quin is similarly new; more of a brawler than his fellows, but glorious with an axe. A Terran who chafes against brothers old and new, he's a fiery presence. Flavius Alkenex is haughty and judgemental, "just on the bearable side of arrogant." Grythan Thorn is similar, a Chemosian with ambitions.
The familiar faces, or the known quantities, are interesting in their own right. Kasperos Telmar, far from the heights he will achieve in "Primogenitor" is the more argumentative side of arrogant, certain of his own opinion and dismissive of even his betters. He's a grating presence, constantly setting off the others around him, which works in the narrative. Crucially the interactions and banter between the warriors never feels forced, but has a natural flow for soldiers/brothers/rivals.
Cyrius is a name familiar to all who know the story of Lucius but outside of a spectral presence in "The Faultless Blade", this is the first time we've seen him as a character. An accomplished swordsman (well he'd have to be), he is far from the command he will hold, and is still learning the lessons that will see him through.
And of course, of course, Fabius comes along. Fabius looms large in the history and future of the Third but Reynolds never lets him outshine the primarch. Here Fabius is still finding his feet, chafing against the legion hierarchy and more concerned with his experiments in the aftermath of the blight. Nicknamed "The Spider", by his fellows, he does spend a lot of time dragging tidbits back to the centre of his web; though forcing him to leave it and engage may be more trouble than it's worth.
Rounding out the Imperial contingent there is Herodotus Frazer; a commander of the Imperial Army and immense skeptic of Fulgrim's plans, much more keen to rain down fire and blood. He's a bellicose presence, though enjoyable as things progress.
And then there is Golconda Pyke. There's not enough that can be said about Golconda Pyke; Primary Iterator, diplomat, spymistress and general badass. Though advanced in years, she's still able to talk straight with Fulgrim and his lot. An old school Iterator, almost a Rogue Trader in demeanour (and through her skill in words and bringing worlds into the Imperium, is almost considered amongst its warlords), she despairs of the moderates who will follow after her; forced into a clean-up and education role as the duty of war becomes almost solely the domain of primarchs and legions.
These characters are hurled into a literally Byzantine web; though one which never feels overdone or too "Planet of Hats". Rather you get something of an impression of a planet of people who are very good at doing things very badly. Where even their plots have corroded to almost uselessness. The historical asides and flourishes are enough to provide flavour, but never to overwhelm; a nest of poisoners, plotters and revolutionaries, with suitably baroque punishments waiting in the wings.
The brevity of action and the focus on intrigue, move and countermove, serves the novel very well. Rather than being a gimmick, the self-imposed restriction allows the novel a slow burn, and a satisfactory ending. Ultimately it becomes almost a cautionary tale, about the dangerous recklessness of hope, the impossibility of utopia, and the cost the enemy can inflict on you despite your best plans.
As an aside; there are a number of interesting tidbits towards the beginning, especially regarding how many primarchs were found by the point of the novel (and quite interestingly who was amongst them), as well as an especially interesting interjection by one of them. I shall say no more.
I heartily recommend this book, which sits as one of the most entertaining, fluid and smooth reads of the Primarchs series thusfar. One which exemplifies Fulgrim's graces and failings, while remaining utterly true (and perhaps more incisive than before) as to what shapes the Third.