Here is the full list of all 27 Masquerada: Songs and Shadows achievements.
Revisit a scene.
Watch the Epilogue.
Clear the final battle.
Listen to all of Vasco's optional dialogues.
Listen to all of Kalden's optional dialogues.
Listen to all of Amadea's optional dialogues.
Listen to all of Tiziana's optional dialogues.
Defeat the Brehon.
Win the duel.
Defeat the Ridiro Queen.
Defeat the Mangiatore.
Listen to all of Leventhos' optional dialogues.
Defeat the Chimera.
Defeat the Ancient Feravaro.
Defeat the Matron.
Defeat the Saltbreather.
Defeat the Antiquarian.
Defeat the Triplets.
Fully upgrade a skill.
Defeat the Greater Bolgia.
Complete the Prologue
Collect all inks and runes.
Collect all the codices.
Respec once.
Practice in the Training Grounds.
Activate 100 Mask abilities.
Trigger 250 Elemental Tags.