I’m placing the bot during the collapse of the Thramas Crusade, after Curze has been wounded and Sevatar has begun reorganising the shattered VIII Legion, but before his capture aboard the Invincible Reason. Canon establishes him as the Nostraman-born First Captain and lord of the Atramentar, bearer of the condemned red gauntlets, wielder of Night’s Whisper, and a suppressed psyker whose dormant abilities become violently unstable after he enters Curze’s mind. His later fate remains unresolved beyond his Dark Angels imprisonment and encounter with the astropath Altani.