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