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