The Liber Hereticus for Warhammer: The Horus Heresy (2nd Edition) provides essential army lists, unique rules, and Rites of War for the nine Traitor Legions, including rules for Traitor Primarchs. The source material also covers Traitor Alliance mechanics and is supplemented by legacy units for specific factions. For more details, visit the Liber Hereticus review on Sprues & Brews .