Here is the full list of all 21 Celestian Tales: Realms Beyond achievements.
Stopped the thief.
Cleaned the ship.
Helped the Fiellite.
Played Aria's story in Old North.
Played Cammile's story in Old North.
Played Isaac's story in Old North.
Played Lucienne's story in Old North.
Played Reynard's story in Old North.
Played Ylianne's story in Old North.
Defeated Abel in combat.
Lost the noble Companionship status.
Rebuilt the fallen House Aramis.
The Emerald King awakened.
Solved all personal stories.
Defeated the Emerald King.
Gave the soldier a divine healing.
Didn't give the soldier a divine healing.
Convinced Orseans to accept the bandit.
Told Orseans the truth.
Sailed north to Kiahonoa.
Sailed south to Ertheros.