The Angel
"Absolute virtue is impossible and the republic of forgiveness leads, with implacable logic, to the republic of the guillotine."
- – Albert Camus
"If we did not feel the bitterness of His anger, we would not so sweetly relish His love."
- – Timothy Rogers
"To the darkness of time I send thee, against the radiance of your being I consign thee, blood cools, fire dies and light rises, the time of the Angel has ended, sleep, my favoured son and dream of purity"
- – The Emperor's incantation of sealing, & goodbye to his first son.
The Angel, not to be confused with one fabulous fucking hawk-boy, is a prototype of the Primarchs created during the Unification Wars and could be said to be the Emperor's first son, colloquially called the Proto-Primarch, Primarch Zero, or the Zeroth. In this way, he can be thought of as a precursor to the Primarchs the same way the Thunder Warriors were precursors to the Space Marines; psychotic, violent, single-minded and incorruptibly loyal to the Emperor and His cause to a fault and completely overshadowing their successors in all ways regarding physical power. Similarly, given that he's a super Primarch who is significantly more closely related to the Emperor himself, it would only be appropriate for the Grey Knights to end up as his Legion with him as their honorary gene-father (if something so absurd were to ever happen), seeing as how both take genetic stock from the Emperor directly rather than from a derivative.
The Angel was created for the express purpose of purging anything Chaotic in nature, making him the Emperor's personal Doomslayer, and while at first he was controllable, it quickly became a Broly and Paragus type of situation where the Emperor couldn't hold the leash on his personal attack dog any longer. This happened after their first fishing trip together in which they slayed caught and sealed away a Demon Prince known as Pharaa'gueotla. After which, the Proto-Primarch went on a genocide run on a nameless backwater planet because he just had all this pent up energy and nothing left to do with it. This transition from fishing to burning ants with a magnifying glass could possibly be motivated by the fact they didn't just slay Pharaa'gueotla when they had the chance and instead opted for the blue balls option of banishing it to the Shadow Realm for no reason.
Whatever his true motive, the Emperor had to take action and seal the Angel away in a sarcophagus by using the carved-up flesh of the daemon prince they caught together as bait on a lure. Apparently, the Angel has such bad tunnel vision that this crap plan actually worked. The Emperor then elected to pushing this failed batch through the paper shredder back on Terra, only for the sarcophagus to be intercepted and smuggled out to an unknown location for unknown purposes to be revealed at a later date never.
Then after the Horus Heresy wrapped up, the Inquisition found the Angel's sarcophagus & let him out to fight the same fucking daemon prince he fought back in the pre-Crusade days, only this time he'd kill it and then decide to do the most Inquisitor thing imaginable, exterminate all humanity before anyone else could turn to Chaos. The Inquisitors, being human, came to the unanimous conclusion that they personally quite enjoy living, and decided to bait the Angel back into the coffin using the dead flesh of Pharaa'gueotla again, and it worked, again. See what government bureaucracy can accomplish when everyone's about to die?
The Angel is also proof positive that Sanguinius' angel wings are no accident of mutation from fucking nuclear radiation or the Warp.
Description
The Angel is what a Primarch would look like if the Emperor didn't bother to nerf any of their capabilities or bother to balance their personalities whatsoever, so not only is the Angel fiercely loyal, it's also unstoppable and can't be reasoned with by the Emperor himself, let alone an average human. The Proto-Primarch is described as being twelve feet tall, having angel wings like Sanguinius, and basically looks like an adolescent version of the Emperor, complete with a blue flaming sword to match Emp's regular flaming sword. Since the Angel embodies all the qualities of the other twenty Primarchs, it's implied that this guy was supposed to be the one gene-son of the Emperor to embark on the Great Crusade with him, but there's not much of a point in ruling over ashes when your prodigy purges anything with the slightest chaotic taint. Such taint happens to include all humanity, since all baseline humans have an innate connection to the Warp due to having souls.
Capabilities
He burns away Chaotic corruption with the literal force of the sun, he holds the Guinness World Record for demolishing cities and armies in the shortest possible time, he wielded a flaming sword just like Emprah and he left a trail of blue fire behind him, which was tremendously inconvenient for everyone involved who wasn't dead, which was nobody. Having a pair of angel wings, he could also fly just like Sanguinius.
Imagine if you took out all the Chaotic corruption from every Primarch and then made them fusion dance together until there was only one left, Zero here is what you'd get. The Angel is the Primarch to end all Primarchs and could probably slay any of them so long as it's a 1:1 fight, except for Vulkan because he has the infinite lives cheatcode. Whether he could take on post-Molech Horus is the real debate. Considering the Angel slew a daemon prince & came out completely unharmed himself, and the Emperor didn't feel like dueling him way back when, and Leman Russ was able to deal a fatal blow to Horus (which he only survived because his Chaos stores made up the difference) in one on one combat, it's probably safe to say that if this guy were to end up on the barge of the Vengeful Spirit during the Heresy that it'd be a different Primarch laying broken and dead on the floor.
So despite being a clear psyker, he's a psyker in the sense that the Emperor is; completely absent of any Chaotic taint. Makes you wonder if the Emperor's brand of psyker happens to be something different from the typical psyker the same way Orks generate their own psychic fields. It also makes you wonder how much of the Chaos-stuff the Emperor took from his time on Molech went into the Angel, if any at all.
Regarding his psychic potency, the question comes up of where he ranks between the Emperor, Magnus and Malcador. No matter what, everybody ranks under Emps by default, but now there's now the possibility that there's a sorta-Primarch more psychically powerful than Magnus. Not much is known of the Angel's psychic might other than his capability to destroy shit wherever he sees it, but he's obviously more potent than say, Lorgar.
Personality
The words to sum up his personality are fanatical, puritanical, loyal, vengeful, determined, devoted, tireless, pertinacious, intransigent, uncompromising, resolute, committed, undeviating and all things that would be totally awesome if not for being undisciplined, unreasonable, uncontrollable & psychotic. In fact, he's so Noblebright that he loops back around to being Nihilist tier Grimdark.
In a way, it could be argued that the Angel is more dedicated to the idea of the Emperor than he is to the Emperor himself, considering how he screamed "You don't deserve the Emperor's love!" as he slaughtered the very people the Emperor wanted to unite under his banner. In fact, in examining such a statement, it could be he was actually jealous of baseline humans getting all the attention despite being obviously unworthy of the Emperor's consideration, much unlike himself which was perfect and beautiful in every way.
The Angel is the answer to the question of "what if the Primarchs were completely pure and brought up under the Emperor's guidance instead of being scattered?" and that answer is "omnicidal maniac." It poses the proposition that maybe having the Primarchs scattered was actually for the best in the end, traitor legions and all.
For the above stated reasons, the Angel is both at once the Imperium's greatest asset (so much so that radical and puritanical Inquisitors fought over who should get to keep him) and it's biggest liability. If he were unleashed onto the battlefield during a Black Crusade, there is no doubt that he, in all of his unwavering devotion and unstoppable power, would undoubtedly shank Failbaddon the Armless in the gut, burn away his flesh in purifying flame and break the daemon sword Drachn'yen over his knee. He would then proceed to kill every other heretic on the battlefield. Then every loyalist Astartes. Then every Guardsman. Then every man, woman and child in the galaxy.
Considering his absolute obsession with expunging all things Chaos, he'd probably make the Sisters of Silence his personal harem, and from there probably start to reconsider his position on humanity's potential for redemption after releasing several millennia of sexual frustration. This reflection would probably end on "I'll just kill everybody except the Blanks."
It also begs the question of what he'd think of his younger brothers. Naturally, the traitor Primarchs, especially Magnus and Lorgar, gotta go. Considering how puritanical he is though, and considering that all 20 Primarchs have already been tainted by the warp to one degree or another, it's probably a full bust with no chances of reconciliation.
There's also the question of, since the Angel is apparently an all-in-one Primarch of sorts, how can his personality clue us in on the Lost and Purged? We know already that the 2nd was shy and reserved, so it can be extrapolated that his puritanical manslaughter & blind, slavish devotion could say something about the 11th since even Konrad Curze wouldn't go as far as exterminating a planet's populace just because the residents there were less than perfect.
He'd probably be chill with the Tau if he hasn't already been given a healthy dose of Xenophobia already, given they practically have no souls to speak of and thus have little to no connection to the Warp.
But more than anything, rest assured he would absolutely hate the Eldar, especially after learning that they single-handedly created their own Chaos God. Not only are they the most prolific psykers in the galaxy, they also have the largest souls of any sentient race, meaning their connection to the Warp is the greatest of all.
Not so clear would be his stance on Tyranids; on the one hand, they're the single most terrifying and threatening foe the Imperium as ever seen and Hive Fleet Leviathan is knocking on Holy Terra's door. On the other hand, the Tyranids have that fancy Shadow in the Warp thing that blots out Chaos energies. On the other hand, they still make use of Zoanthropes.
Then there's the question of how he'd respond to seeing his own father interned on the Golden Throne, which considering his bottomless devotion to ol' Emps, would probably send him into an earth-shattering mental breakdown on the spot, causing him to sobbingly vow revenge against whoever did it, only to fly into a rage at finding out that this "FUCKING HORUS" person is already long dead and gone, only to instead settle on slaughtering the daemon Primarchs and their legions.
Clearly, the only true course of action is to just drop him into the Eye of Terror and watch as it shrivels away in mere days as he slaughters every Chaos worshiper in that region of realspace. Then drop him off at Commorragh for good measure.
Source
| The Primarchs of the Space Marine Legions |
|---|
 Loyalist Corvus Corax - Ferrus Manus - Jaghatai Khan Leman Russ - Lion El'Jonson - Roboute Guilliman Rogal Dorn - Sanguinius - Vulkan |
 Traitor Alpharius/Omegon - Angron - Fulgrim Horus - Konrad Curze/Night Haunter - Lorgar Magnus the Red - Mortarion - Perturabo |