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