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