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