Here is the full list of all 51 Talisman: The Horus Heresy achievements.
Defeat Horus
Defeat the Emperor
Complete all of Roboute Guilliman's goals
Complete all of Corvus Corax's goals
Complete all of Vulkan's goals
Complete all of Garviel Loken's goals
Complete all of Alexis Polux's goals
Complete all of Angron's goals
Complete all of Mortarion's goals
Complete all of Ezekyle Abaddon's goals
Complete all of Konrad Curze's goals
Complete all of Kor Phaeron's goals
Successfully navigate The Eye of Terror
Successfully navigate through The Maelstrom
Smash through the Naval Blockade at Luna
Defeat the forces of Nikaea
Defeat the forces of Signus Prime
Complete an Errant Quest
Complete an Infernal Quest
Defeat the forces at Damocles Spaceport
Defeat the Favoured of Horus
Defeat the Legio Custodies
Survive the Perilous Wastes
Trade a Talisman
Use three Strategems in one turn
Reach level 50
Reach level 100
Complete all of Sigismund's goals
Complete all of Kharn's goals
Complete all of any Praetor's goals
Complete all of Sevatar's goals
Complete all of Artellus Numeon's goals
Complete all of Erebus's goals