How does Castellan Garran Crowe join the game if you buy the Castellan Champion Edition?
Castellan Garran Crowe will become available to use during a timeline event in the campaign for owners of the Castellan Champion Edition version of Warhammer 40,000: Chaos Gate - Daemonhunters.
You will just need to play the game normally until this event appears.
After this, Castellan will be available to select from the Barracks for future missions.