Anger

Anger is a zero-cost Ironclad attack that deals 6 damage (8 upgraded) and adds a copy of itself to your discard pile. The self-replication mechanic makes Anger a snowball card: each time you play it, there's one more copy waiting in your discard. In a small, fast-cycling deck, Anger can fill your hand with free damage very quickly, and paired with Exhaust-synergy relics or the Fiend Fire, those extra copies become a resource.

The downside is deck inflation — without a plan to use or exhaust the copies, Anger floods your deck with redundant cards that bloat draw cycles. It works best in aggressive decks with very few cards, where each draw is impactful and you want to maximize damage per Energy. Upgrading for +2 damage and another free copy is solid but not critical.