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