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