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