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