Here is the full list of all 31 Knights of Grayfang achievements.
Watched the opening.
Investigated the cause of the appearance of creatures that should not be in the temple.
Escaped from crisis with the sudden help of a young man.
The mysterious youth became a member of the party.
Investigated the crucial base separately from the main unit.
Was officially deployed as a force in the Temple War.
What was the voice of the deity heard in the space-time rift?
Encountered the deity of monsters, Morgen.
The true identity of the Dark Witch Adelina was Queen Anamaria.
The true identity of the Dark Knight Engelbert was King Edwahl.
Overcame the trial of the Twilight Deity Clepius and received the divine power.
The true identity of the king's steward, Ghislain, was the Undead Deity Mortinos.
Obtained a ship and headed to the island where Mortinos resided.
Was imprisoned in the Dimensional Prison by Clepius, who feared the power of the vampires.
Morgen, fused with the other deities, revealed a series of truths.
Reached the ending.
Collected 50 treasure chests.
Collected 100 treasure chests.
Collected 150 treasure chests.
Defeated 100 enemies.
Defeated 500 enemies.
Defeated 1,000 enemies.
Achieved all the quests.
Cleared the Arena Beginner.
Cleared the Arena Intermediate.
Cleared the Arena Advanced.
Cleared the Arena Expert.
Cleared all the Beginner Awards.
Cleared all the Intermediate Awards.
Cleared all the Advanced Awards.
Cleared all the Expert Awards.