Here is the full list of all 18 Warring States achievements.
Capture an Outpost.
Complete a story mission without Archers.
Complete a story mission with only Halberdiers.
Complete a story mission without reinforcing a unit.
Complete a story mission without using a special attack.
Complete a siege story mission using only Siege Towers for equipment.
Complete the story.
Destroy a Stone Gate.
Destroy a Wooden Gate.
Complete a story mission without losing a unit.
Complete a story mission in under 20 turns.
Achieve S Rank on a story mission.
Achieve S Rank on all story missions.
Succesfully Rally a broken unit.
Win a Battle Mode game against AI.
Win a Capture The Flag game.
Win an Attacker vs Defender game.
Win an Attacker vs Defender Siege game.