I don’t think it’s fair to call Slay the Spire (StS) a clone. While Card Quest introduced a lot of the key elements years earlier, StS adds enough innovation that it feels like a totally different game. Definitely would be more fair to say StS popularized a lot of the mechanics rather than invented/pioneered them though.
Why there are 861 roguelike deckbuilders on Steam all of a sudden (arstechnica.com) angielski