Here is the full list of all 19 Symphony of War: The Nephilim Saga achievements.
Defeat all enemies in Chapter 12.
Complete the main story on Captain difficulty.
Complete the main story on Warlord 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.
Army size reaches 150 Units.
Form a Bond relationship.
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.
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.