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