Here is the full list of all 38 Souldiers achievements.
Complete all side quests.
Collect all secondary weapons.
Defeat 50 enemies using secondary weapons.
Complete the game on Warrior mode.
Complete the game as a Scout.
Defeat Beigon on Soldier or Warrior mode.
Upgrade your protection the highest level.
Upgrade your weapon to the highest level.
Reveal 100% of every map.
Find all of the hidden rooms.
Defeat Agginox on Soldier or Warrior mode.
Defeat all Dark Warriors.
Collect all Dark Crystals.
Defeat Galath a second time.
Destroy 3,000 environmental objects.
Defeat Ratatosk on Soldier or Warrior mode.
Use 100 potions.
Collect all orbs in the game.
Defeat Project S on Soldier or Warrior mode.
Discover 50 hidden rooms.
Defeat Sangrigor.
Defeat Brigard.
Defeat Birk on Soldier or Warrior mode.
Inflict altered states on your enemies 50 times.
Defeat 1,000 enemies.
Defeat Babylon on Soldier or Warrior mode.
Defeat all Royal Scorpions.
Defeat the Minotaur
Defeat Iktala on Soldier or Warrior mode.
Be revived by the Valkyries after falling in combat.
Destroy 10,000 environmental objects.
Defeat 5,000 enemies.
Complete the game as an Archer.
Complete the game as a Caster.
Complete the game as all three classes.
Unlock all skills.
Complete the Bestiary in your Encyclopaedia.
Finish a game on Game+ mode.