Here is the full list of all 24 Nadir: A Grimdark Deckbuilder achievements.
Defeat King in Yellow
Play the Saint's Blood card
Defeat Lilith
Defeat Chernobog
Defeat Asmodeus
Defeat Minos
Unlock Hernan Cortes as a playable character
Defeat Moloch
Defeat Koschei the Immortal
Earn any Desires for the first time
Earn any Idols for the first time
Defeat Beelzebub
Defeat Belzebub
Defeat Abaddon
Defeat the Gunnery Demon
Defeat Fury
Obtain any Rare card
Defeat Feaster from Afar
Unlock Vlad Tepes as a playable character
Earn any Skulls for the first time
Earn any Relics for the first time
Purchase any card in the shop
Possess a Damned as a reward
Earn any Filth for the first time