Lesser Horus Heresy (40K) RAR

[The Grim Squeaker]

A central element of the Horus Heresy books is how easy it would have been for things to go differently, the thought occured to me as to what would be the possible consequences of the following two changes , both of could easily have happened:

• 1. Fulgrim does not acquire the Daemon possessed sword. (Assume the temple was destroyed from orbit, or that someone else was at the attack and acquired the sword).
• 2. The Emperor lets Magnus know that he's working on penetrating the Webway, and that's why his defenses must Not be breached from the warp. Magnus still tries to warn his father of Horus's treachery, but he doesn't try to penetrate the defenses around the Imperial Dungeons. This means that Terra does not become a borderline Daemon world due to the breached portal.

Both of these things could have happened quite easily (albeit, more so the former than the latter).
Likely consequences:
1: Fulgrim almost certainly does not fall to Chaos or join the Heresy (The Daemon stated quite plainly that without it's influence Fulgrim would have fought Horus and tried to warn the Emperor).
Without his support, Ferrus Mannus may survive the Isstvaan dropsite massacre (which will still likely happen, albeit with reduced severity. I don't remember whether the Emperor's children were part of the first or second wave).
An additional change is that Guilliman, primarch of the Ultramarines and custodian of the Imperium after the end of the Heresy will not be poisoned unto near death by a possesed Fulgrim.
The emperor's children while skilled weren't that numerous, and their contribution to the siege of Terra was negligible (they spent the time mainly massacring civilians and snorting the remains). The big difference would be the far greater amount of surviving loyalist Primarchs, and the superior power structure of the Imperium.
(I'm ignoring Horus's Anathema, Fulgrim almost certainly wouldn't have been given it if he didn't turn traitor).

2. The Emperor, the Custodians and the sisters of silence (And Malcador) do not have their resources and energies severely sapped by stemming the flow of daemons through the gate. Whether the Thousand sons would still have been sanctioned as severely, resulting in their decimation (Well, ninefold decimation) is another matter. It's likely though, since Horus would have had more trouble twisting any possible commands from the Emperor that didn't start as "What have they DONE!" etc).

[Manus Celer Dei]

1: Fulgrim almost certainly does not fall to Chaos or join the Heresy (The Daemon stated quite plainly that without it's influence Fulgrim would have fought Horus and tried to warn the Emperor).
Without his support, Ferrus Mannus may survive the Isstvaan dropsite massacre (which will still likely happen, albeit with reduced severity. I don't remember whether the Emperor's children were part of the first or second wave). .

The Emperor's Children were among the initial defenders at Istvaan. Without them, Horus'd probably just pull another one of his traitor legions to take their place, but the Drop Site Massacre would play out in a fundementally different way. The only reason the Iron Hands, Raven Guard and Salamanders charged in on their own was because Ferrus Manus was so pissed at Fulgrim; without that motivation I doubt they would have been so reckless and wouldn't have been caught so flatfooted by the arrival of the other traitor legions. If the loyalist legions had the Emperor's Children on their side and weren't so thoroughly ambushed they probably would've been able to retreat with more of their fighting strength intact and would likely have remained an active force for the rest of the Heresy rather than just sitting around moping because most of their legion were dead.

[The Grim Squeaker]

1: Fulgrim almost certainly does not fall to Chaos or join the Heresy (The Daemon stated quite plainly that without it's influence Fulgrim would have fought Horus and tried to warn the Emperor).
Without his support, Ferrus Mannus may survive the Isstvaan dropsite massacre (which will still likely happen, albeit with reduced severity. I don't remember whether the Emperor's children were part of the first or second wave). .

The Emperor's Children were among the initial defenders at Istvaan. Without them, Horus'd probably just pull another one of his traitor legions to take their place, but the Drop Site Massacre would play out in a fundementally different way. The only reason the Iron Hands, Raven Guard and Salamanders charged in on their own was because Ferrus Manus was so pissed at Fulgrim; without that motivation I doubt they would have been so reckless and wouldn't have been caught so flatfooted by the arrival of the other traitor legions. If the loyalist legions had the Emperor's Children on their side and weren't so thoroughly ambushed they probably would've been able to retreat with more of their fighting strength intact and would likely have remained an active force for the rest of the Heresy rather than just sitting around moping because most of their legion were dead.

Is there any information on whether they suffered more casualties in the initial fight or from the second wave of traitors? I remember it being the latter.
I don't remember them charging in just due to it being Fulgrim, rather that they did it due to not knowing the they'd end up being outnumbered and stabbed in the back rather than having the advantage of numbers.

[J Ryan]

1: Fulgrim almost certainly does not fall to Chaos or join the Heresy (The Daemon stated quite plainly that without it's influence Fulgrim would have fought Horus and tried to warn the Emperor).
Without his support, Ferrus Mannus may survive the Isstvaan dropsite massacre (which will still likely happen, albeit with reduced severity. I don't remember whether the Emperor's children were part of the first or second wave). .

The Emperor's Children were among the initial defenders at Istvaan. Without them, Horus'd probably just pull another one of his traitor legions to take their place, but the Drop Site Massacre would play out in a fundementally different way. The only reason the Iron Hands, Raven Guard and Salamanders charged in on their own was because Ferrus Manus was so pissed at Fulgrim; without that motivation I doubt they would have been so reckless and wouldn't have been caught so flatfooted by the arrival of the other traitor legions. If the loyalist legions had the Emperor's Children on their side and weren't so thoroughly ambushed they probably would've been able to retreat with more of their fighting strength intact and would likely have remained an active force for the rest of the Heresy rather than just sitting around moping because most of their legion were dead.

Is there any information on whether they suffered more casualties in the initial fight or from the second wave of traitors? I remember it being the latter.
I don't remember them charging in just due to it being Fulgrim, rather that they did it due to not knowing the they'd end up being outnumbered and stabbed in the back rather than having the advantage of numbers.

From my memory of Fulgrim, First Heretic and Flight of Ravens it was definitely the latter.

The 3 loyalist legions had taken a beating but were still had the vast majority of their troops. It wasn't till they fell back to the forts the other legions had prepared, when they got caught in the cross fire and truly massacred.

Also Ferrus essentially did charge straight into the middle of the Emperor's Children with his Elite Guard as his number one priority was getting close enough to Fulgrim to take him out.