Here is the full list of all 44 Mages Initiation: Reign of the Elements achievements.
Kill 500 enemies.
Earn all Fire class Bonus points.
Extinguish the Redcaps' camp fire.
Earn all Water class Bonus points.
Earn all Earth class Bonus points.
Finish the game with all 4 classes.
Finish the game with max XP / score.
Max out all your stats.
An ally survives.
Earn all Air class Bonus points.
Kill one of each monster type.
Pick all mushroom clusters in the forest.
Complete all class-based side quests with optimal outcomes.
Optimally complete the Air side quest.
Optimally complete the Water side quest.
Kill 100 enemies.
Optimally complete the Earth side quest.
Kill 50 enemies.
Kill only the bosses (no regular monsters).
Beat the game without equipping any extra gems or items (after the initial tutorial).
Find and read all books and notes.
Complete the game.
Defeat the Big Bad.
Both allies survive.
Complete the third trial.
Make a red delivery to the Greencaps.
Reject a dark deal.
Find all three "Tear" class brooches.
Win the maximum number of Demon's Deal rounds.
Ele'port to each pillar stone location.
Return a borrowed item.
No sacred avian was harmed.
Complete the second trial.
Earn your third spells from the Sphere of Knowledge.
Complete the severed circle story branch.
Optimally complete the Fire side quest.
Earn your second spells from the Sphere of Knowledge.
Complete the first trial.
Spare a tainted life.
Acquire one of each drink type at the tavern.
Win a hand of Demon's Deal.
Beat both Mage sparring partners.
Earn your first spells from the Sphere of Knowledge.
Kill 1,000 enemies.