Podcast
The 40k Lorecast
Brad Chester referenced the book while discussing the Custodians, noting that it helped clarify long‑standing uncertainty about whether they were created before, during, or after the Primarch project. He highlighted the book’s detail that fewer than one in a thousand survived the creation process and that the Emperor only kept the absolute best. The discussion was informational rather than a strong endorsement.
Episode: Episode 2- History of Mankind - The Great Crusade...
The lore surrounding the Custodians was discussed, mentioning the book and that for a long time, it was unclear whether they were created before, during, or after the Primarch project, and that less than one in a thousand survived the creation process.
and i know we've got the new custodians book in 40k but the lore for a long time was these guys were either before during or after it depends on which book you pick up but what they are is the perfection of him trying to distill himself into physical form and the biggest thing about this is we could make only a very limited amount of this because everyone died from doing less than one in a thousand survived well it's just not even one of a thousand but also the emperor again being kind of a dick he was also just throwing some of these in the garbage he was just full full sparta throwing them off the cliff even the ones that survived he only really wanted the best of the best of the best at that point in time is he handpicked the custodes because he wanted these basically unachievable these were i feel like every custodian that happened was an accident basically you're like i can throw this dart down through this building a mile away catch this gust of wind every trick shot video we've ever seen these guys do it on the first take yeah that's what they can do and they are perfect in every way