Here is the full list of all 27 Kingsway achievements.
The base game contains 21 achievements, and there is 1 DLC pack containing 6 achievements.
Saved the world as the Mage
Ending #3
Saved the world as the Adventurer
Ending #2
Highest possible reputation
Activated all monoliths
Saved the world as the Warrior
Ending #1
Activated all Guardian Beacons
Level 10 Adventurer
Level 20 Adventurer
Saved the world as the Rogue
Saved the world as the Beastkin
Saved the world as the Demonblood
Saved the world as the Ascended
Saved the world as the Worthless
Ending #4
Ending #5
Lowest possible reputation
Learn an ancient spell
Fully upgraded a skill
Saved the world as the Necromancer