Castle of cards - Defence apocalypse LitRPG

Ray wakes in Kalandra, a brutal world run by an omnipotent System that treats survival like a game. His task is simple: build a fortress, survive monster waves, and prove humanity’s worth. Granted a unique army made of living cards and a rare class known as a Card Mage, Ray must master an ever-shifting deck of spells, summons, traps, and curses while turning a fragile wooden shack into an unbreakable stronghold.