Here is the full list of all 30 Curse of the Dead Gods achievements.
Write all Bestiary entries with their complete sketches
Equip the three weapons slots with Cursed weapons
Make 10 Blood Offerings during a single exploration
Become the new Champion of Death
Complete 10 different "Special Events"
Complete any exploration with 50 or more Perception
Lift the Final Curse
Complete any exploration with 50 or more Constitution
Unlock all Weapon Altars upgrades
Get 3 successful Parries in less than 2 seconds
Unlock 20 Blessings of the Dead Gods
Complete any exploration with 50 or more Dexterity
Defeat Clovis Pardieux, Champion of Death
Defeat the Dark Avatar of the Eagle
Defeat the Dark Avatar of the Serpent
Equip a hidden Champion weapon
Defeat the Dark Avatar of the Jaguar
Unlock 20 Forsaken Weapons
Defeat Ratyapu, the Abomination
Defeat Malok paal, the Flesh Monstrosity
Write 5 Bestiary entries
Start a "Special Event"
Defeat Litz & Nepac, the Cursed Twins
Unlock 5 Forsaken Weapons
Defeat K'ax taca, High Lord of the Storm
Defeat Xucat', the Witch
Unlock a Blessing of the Dead Gods
Achieve a x10 "Greed Kill" series
Defeat Xak'olchir, the Blood Hunter
Complete the room of Trials