Here is the full list of all 47 Monastery achievements.
Beat the Devil.
Beat the Alpha Wolf.
Beat Gaia.
Beat the Giant Mutant.
Beat the Ghoul Queen.
Beat the Undertaker.
Reach Sword Mastery level 10.
Reach Shield Mastery level 10.
Reach Heavy Armor Mastery level 5.
Reach Master of Broadsword level 10.
Reach Master of Rapier level 10.
Reach Master of Cutlass level 10.
Reach Master of Buckler level 10.
Reach Master of Kiteshield level 10.
Reach Master of Heater level 10.
Reach Master of Splint Mail level 10.
Reach Master of Chain Mail level 10.
Reach Master of Plate Mail level 10.
Max out all sword masteries.
Max out all heavy armor masteries.
Max out all shield masteries.
Collect every variation of the Broadsword.
Collect every variation of the Rapier.
Collect every variation of the Cutlass.
Collect every sword.
Collect every variation of the Kiteshield.
Collect every variation of the Heater.
Collect every variation of the Buckler.
Collect every shield.
Collect every variation of the Splint Mail.
Collect every variation of the Plate Mail.
Collect every variation of the Chain Mail.
Collect every heavy armor.
Use a torch to explore the pathways on the Crossroads.
Change your default equipment.
Complete a successful run with a fully equipped character.
Lose a run by dying.
Change a character's background.
Complete the tutorial.
Complete a successful run.
Complete a successful run by only dealing thorns damage.
Change your character's appearance.
Beat a boss without taking HP damage.
End a successful run with only 1 HP remaining.
Deal 50 damage in one hit.
End every turn with at least 1 stamina left throughout a whole run.
Hoard 1000 shards.