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