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.
Highest possible reputation
Activated all monoliths
Saved the world as the Adventurer
Ending #1
Level 20 Adventurer
Activated all Guardian Beacons
Level 10 Adventurer
Saved the world as the Warrior
Saved the world as the Mage
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 #2
Ending #3
Ending #4
Ending #5
Lowest possible reputation
Saved the world as the Necromancer
Fully upgraded a skill
Learn an ancient spell