Editing Gene-seed (section)

==== Imperial Fists (VII Legion) ====
{{Main|Imperial Fists}}
* Missing Betcher's Gland (no acid spit).
* Missing Sus-an Membrane (no suspended animation).
* Possibly increased pain tolerance and/or a tendency towards masochism.

Despite missing two organs, the Imperial Fists gene-seed is considered to be amongst the most stable and most manly sources. It is the second most desirable source of gene-seed for Foundings. ''Second'' to the Ultramarines, of course. The Fists however, display a constant need to punish themselves for perceived failures, both real and imagined. While this is barely noticable in the primogenitor chapter, several successors manifest more pronounced versions of this flaw.

Missing Sus-an Membrane is also a big deal, as it removes a "safety net" most other chapters have, and most times when Imperial Fist "falls in battle" he actually dies for good instead of passing into coma from which he could be brought back later if marines win the engagement and recover his body. That's why Imperial Fists and all their successor chapters need multiple recruiting worlds. Silver lining though is that sons of Dorn don't run the risk of being captured by Chaos and brainwashed if they fall in battle and their body is then recovered by forces of Chaos instead of allies.

* Complicated by the [[War of the Beast]], in which the Imperial Fists were ''literally wiped out to the last man.'' In the aftermath, their successors got together to donate gene-seed to reconstitute the chapter, making their post-Beast gene-seed a chimeric melting pot of separate mutations and oddities. Additionally, it's not confirmed whether the mechanicus were holding and offered stocks of original, untainted gene-seed as part of this process. Even [[Primaris Marines|Primaris]] marines who were made with the original stuff (and in some cases are original legionaries) may be different as it's not clear what effect Primarisification has on the gene-seed or if it's possible to make firstborn from it. In short; the Imperial Fists gene-seed may be unique among loyalist chapters in that it [[Grimdark|simply no longer actually exists.]]
** Except, hilariously, in some [[Iron Warriors]], who take a particular spiteful delight in [[Blood Ravens|stealing]] their arch-nemeses' progenoids.

===== The Excoriators =====
* A mutation with some similarities to the Blood Angel's Black Rage, known as "Dorn's Darkness.". Those affected enter a dream-like state in which they relive the bottomless woe and paralyzing fear of Dorn's darkest moment: the moment he saw the Emperor near death after the battle aboard the ''Vengeful Spirit''. They can't care for themselves while in this state, and don't recognise anything happening around them. 
** Basically, if the Black Rage is unbridled [[RAGE]] unbound, Dorn's Darkness is crippling, ruinous depression.

===== Crimson Fists =====
* A mutation similar to Dorn's Darkness, known as "Only Honour In Death". The "curse" causes a massively increased willingness to fight to the last, holding their ground with a siege-like mentality which will see them triumph or die in the attempt the more foes that the Astartes faces, and the longer they are in combat, the more likely and stronger the curse becomes, making them feel emotions much like what Dorn felt during the [[Perturabo#Iron_Cage_Trolling|Iron Cage Incident]]. When succumbing to the "curse" the affected Battle-Brother sees only death: the death of their comrades, the death of the world, and the death of their foes. The curse is seen to come in three stages:
** Stage 1 - No Retreat. As the odds mount so does the Battle-Brother's stubborn refusal to retreat, seeing only the glory and honour in defeating such overwhelming foes if even the barest glimmer of victory remains. The Battle-Brother will even continue to fight, even if the Codex Astartes does not support that action, until there is no hope of victory left.
** Stage 2 - Suffer not Defeat. The Battle-Brother decides [[Red Scorpions|he'd rather die fighting than take a step back or listen to reason]], even when there's little reason to do so.
** Stage 3 - Unto Death. [[Blackshield|The Battle-Brother becomes hell-bent on sacrificing himself for victory or the safety of his brothers, regardless of how badly hurt he is.]] He'll happily accept suicide missions or near-enough suicidal tasks. Essentially Black Rage 2: Fists Boogaloo.