Full list of all 53 Fell Seal: Arbiter's Mark achievements.
The base game contains 43 achievements, and there is 1 DLC pack containing 10 achievements.
Unlock the Marked Class
Get the second ending
Open all treasure chests
Master all 6 special badge Classes
Get the first ending
Defeat Morgaine
Master all 20 base Human Classes
Master all 19 base Monster Classes
Complete the Ancient Path
Unlock all 20 base Human Classes
Master all Human story character Classes
Cleanse the Cursed Shield
Complete the Obelisk riddle
Open 50% of treasure chests
Obtain all gadgets
Win the second Tournament
Craft a final-tier weapon
Visit the fifth Relic
Visit the fourth Relic
Defeat an enemy with a Berserk, Charmed, or Mind-Controlled enemy
Recruit Kairu
Complete the Halloween encounter
View all optional dialogue events
Save Somier a second time
Recruit Katja
Visit the third Relic
Unlock the Spymaster Class
Defeat Lady Anquine
Drown an enemy
Defeat an enemy with falling damage
Recruit Bzaro
Defeat at least 4 enemies with a single hit
Win the first Tournament
Visit the second Relic
Use your first Class badge
Unlock the Demon Knight Class
Recruit Yates
Master any Class
Defeat a unit with its Elemental weakness
Visit the first Relic
Defeat an enemy by using a Counter Ability or Thorns
Craft your first item
Change Class at least once
Defeat an enemy with a Pet Effect.
Master all 22 Monster Variants.
Master the 3 new Human Classes.
Enlist each of the base 18 recruitable Monster types.
Complete all unique Hunts and large-scale battles.
Complete all Missions.
Complete an encounter deploying only Monsters.
Fully upgrade all 5 regions.
Complete 100% of Missions in one region.
Build a Guild Upgrade.