Here is the full list of all 82 SOVL achievements.
The base game contains 70 achievements, and there are 3 DLC packs containing 12 achievements.
Complete the campaign with the Abyssal Herald
Complete the campaign on the hardest difficulty with the Abyssal Herald
Complete the campaign with the Abyssal Prince
Complete the campaign on the hardest difficulty with the Abyssal Prince
Complete the campaign with the Darkborn Assassin
Complete the campaign on the hardest difficulty with the Darkborn Assassin
Complete the campaign with the Northmen Packleader
Complete the campaign on the hardest difficulty with the Northmen Packleader
Complete the campaign with the Paladin
Complete the campaign on the hardest difficulty with the Paladin
Complete the campaign with the Maiden
Complete the campaign on the hardest difficulty with the Maiden