Editing Gene-seed (section)

==== Marines Errant (Ultramarines Successors) ====
* Suffer a psychological flaw called "Crusaders Call", which makes them unable to refuse the call for a crusade. This flaw manifests in three stages:
** Stage 1 - Unending Valour: The Battle-Brother has become filled with pride in the history of his Chapter's bravery and devotion and sees his own existence as a vital part of continuing its traditions. When his squad is required to do its duty he will make sure that it is carried out, squashing any doubt his fellow Battle-Brothers might have or any weakness they might show in the face of honour.
** Stage 2 - Duty through Sacrifice: True duty can only be proven in death or an equally potent sacrifice, a fact which is known to all true servants of the God-Emperor. The Battle-Brother knows that to prove himself he must be the one to stand in the way of the blade or shield his comrades from the blast, so that there can be no doubt about his devotion or his loyalty to the Emperor.
** Stage 3 - Lead the Charge: In boarding actions, the greatest honour goes to those first through the breech and first to face the foe. The Battle-Brother accepts that he must take this role as his honour demands it, and it is just another way to prove his courage and loyalty in the eyes of his peers. If there is a choice or a chance to lead a charge or be the first to face the enemy, the Battle-Brother must take it. Furthermore he will seek out such opportunities, volunteering for dangerous duties if they mean he will get to lead others into the fray. In combat, the Battle-Brother will also seek out the most dangerous or powerful-looking foes, even at the cost of ignoring closer or more pressing enemies to his brethren's tactical disadvantage.

It is unclear if these are actually geneseed flaws or cultural issues ascribed to geneseed.