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