Board Thread:Warhammer 40k Novels/@comment-27376167-20151210113237/@comment-26603023-20160617174323

As far as war between the Legions, let's not forget the plethora of references to how unthinkable it was for the Fallen Primarchs to turn on the Emperor, and how the Legionaries were in such shock and horror at having to fight fellow Space Marines.

There's still the possibility that the Lost Primarchs' Legions were folded into existing Legions, but as far as their Legions being exterminated...

As far as the "defied the Emperor, got put down" theory, Konrad was all serial-killer/mass-murderer, Jaghatai went off and did his own thing, Magnus got away with dabbling with the Warp for a looong time, and so on. It's pretty established that the Emperor didn't care for the specifics, as long as there was conquering being done, and religions being quashed. Hell, Angron literally had to be forced to take his Legion, and just constantly threw temper tantrums. There is the "refused to conquer" thing, but I'll get back to that...

I have serious issue with one of the Lost being eliminated for refusing to abandon their beliefs, because Lorgar. I mean, he wasn't even brough to heel until his Vaticanization of every world he conquered interfered with his daddy's plans of conquest.

I also don't see the "consorted with Aliens", as the Crusade-Era policy was waaaay less restrictive on interaction with xenos, and even some mutants and more extreme abhumans.

The mutation argument, I don't know. I mean, Magnus' Legion was apparently going all Spawn-y, but still able to keep it in their Power Armor. Plus, all the Primarchs were exposed to the Warp (by design, even), and if Ol' Empy was cool with Sanguinius's wings, Leman Russ going Teen Wolf, Magnus' unibrow, and Vulkan looking like a charred steak, then...

Much more likely to me, for at least one of them, is that they were killed before they matured, likely almost immediately after planetfall (even Lil' Sanguinius, three weeks old but the size of a 3-year-old, killed a rad/fire scorpion with his adorable little bare hands). This would explain why they were still fairly unsure if the primarchs could really be killed (until Fulgrim made Ferrus Manus into Ferrus Headlus), because the Primarchs in their final forms had been basically death-proof.

Another consideration is that the Emprah was a cold-blooded bastard, and just wasn't satisfied with one of them   (or both). I mean, think about it: Guilliman, politician. Dorn, fortifications. Perturabo, siegecraft. Curze, assassin. Lorgar, demagogue. Russ, enforcer. Corax, super-spy. Mortarion, HazMat. And so on. Every Primarch had something different, or at least useful. Hell, even bat-shit Pinhead/Angron had his strength and rage. All of them contributed to the Crusade. So, what if one or two didn't land on a deathworld/warworld/etc, so didn't develop the skills/powers needed to survive, and so was a great big disappointment to their warmongering cell donor? It's never been said that midblasting Horus was the first time he'd ever erased someone from existence.