Here is the full list of all 38 Souldiers achievements.
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.
Use 100 potions.
Defeat Sangrigor.
Defeat Brigard.
Defeat Birk on Soldier or Warrior mode.
Defeat 50 enemies using secondary weapons.
Discover 50 hidden rooms.
Destroy 3,000 environmental objects.
Defeat Babylon on Soldier or Warrior mode.
Inflict altered states on your enemies 50 times.
Defeat all Royal Scorpions.
Defeat 1,000 enemies.
Be revived by the Valkyries after falling in combat.
Defeat the Minotaur
Defeat Iktala on Soldier or Warrior mode.
Destroy 10,000 environmental objects.
Find all of the hidden rooms.
Defeat Agginox on Soldier or Warrior mode.
Defeat all Dark Warriors.
Complete the game as a Scout.
Complete the game as an Archer.
Complete the game as a Caster.
Complete the game as all three classes.
Unlock all skills.
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.
Complete the game on Warrior mode.
Finish a game on Game+ mode.
Defeat Beigon on Soldier or Warrior mode.