How do you play The Ironclad in Slay the Spire 2? The Ironclads were a fierce group of warriors who had been at war with rival clans for centuries. In hopes of swinging the odds in their favor, The Ironclad sought power from divine forces to help his clan succeed. After making a pact with a demon, The Ironclad became unstoppable, single-handedly destroying his enemies and allies in a blind fury. The Ironclads were no more, and only The Ironclad remained. As one of the three returning Slay the Spire 2 characters, The Ironclad has several new tools to slaughter his foes. From the new Vulnerable cards that reward you for keeping the pressure on, to Exhaust builds that thin out your deck in exchange for powerful bonuses, the best Ironclad builds are designed to help you unlock all the Ascension levels.