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