Editing MidHammer 40,000 (section)

===Chapters, Legions, and the Codex Astartes===
The Codex Astartes still exists in this universe, but, mostly because the Lorgar Letdown wasn't as devastating as the Horus Heresy and there were more primarchs that could oppose Guilliman, it's not universally adopted as in the original 40k.

Basically, after the Lorgar Letdown, a fight breaks out between Horus and Guilliman on how to handle the remaining legions, Guilliman of course stands for his chapters style, Horus instead wants to keep the legions as they were during the Great Crusade. This conflict between the two  primarchs doesn't spark another civil war because Big E, though very weakened by his recent injuries, intervenes to save the day and find a compromise.

Currently in the Imperium Codex Astartes and Legio Astartes coexist with the first ones more suited for planetary scale operations and the second ones for sector-wide offense and defense. Loyalist marines are "split" into these two different ideologies depending on which idea their primarchs supported.

Big question: Legion of the Damned. Does it become the Legion of Martyrs? In this setting, perhaps anyone can get a second chance if you were sufficiently hardy in terms of soul and mind.