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