Here is the full list of all 19 Symphony of War: The Nephilim Saga achievements.
Complete the main story on Captain difficulty.
Have 9 Units in one Squad.
Army size reaches 150 Units.
Reach Max Faction Rank.
Unlock all Techs in a single playthrough.
Surrender 200 enemy Units in a single playthrough.
Use a Proof of Merit on a Unit.
Hire a Unique Mercenary.
Reach Faction Rank 9.
Defeat Beatrix in Chapter 11.
Class change to Tier 3.
Form a Bond relationship.
Find or purchase an Artifact of Legendary rarity.
Class change to Tier 2.
Reach Faction Rank 4.
Complete the main story on Warlord difficulty.
Surrender all the Imperial Squads in Chapter 27.
Rescue all 4 children in Chapter 15.
Defeat all enemies in Chapter 12.