Offering

Offering is a 0-cost Rare Skill card for the Ironclad that causes you to lose 6 HP, gain 2 energy, draw 3 cards, and then Exhaust itself. This is one of the most powerful utility cards in the game, providing massive card advantage and energy at the cost of HP.

Offering triggers Rupture for Strength, Crimson Mantle for Strength and Block, and Inferno for AoE damage. The 3 cards drawn help find Fiend Fire, Demon Form, or other key pieces. The 2 energy lets you play expensive cards like Colossus or Barricade on the same turn. The self-Exhaust triggers Dark Embrace and Feel No Pain. In virtually every Ironclad deck, Offering provides an explosive turn of activity.

Offering is one of the Ironclad's best cards, period. Pick it in almost every deck unless your HP is critically low throughout the run. Against Ceremonial Beast and other bosses where a single explosive turn can win the fight, Offering provides that burst. The Ironclad's Burning Blood relic heals 6 HP at the end of combat, exactly offsetting Offering's cost. It fits Strength builds, Exhaust builds, Block builds, and self-damage builds equally well.