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