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