Slay the Spire 2 Aggression — Ironclad Power Card Guide

Published 2026-09-205 min read

Aggression in Slay the Spire 2: the Ironclad Rare Power that recycles random Attacks from your discard pile, upgraded — stacking rules and best decks.

Aggression is an Ironclad Rare Power that players often search as "spell aggression" — the card (and the buff it grants) recycles Attacks from your discard pile back into your hand, upgraded, every turn. It's the engine behind the looplean Ironclad decks that never run out of attacks. Full mechanics below.

A Slay the Spire 2 combat scene showing cards being played
Your discard pile is not a graveyard. It's a magazine.

The card: Aggression

  • Class / Rarity: Ironclad, Rare Power
  • Cost: 1 energy; Innate when upgraded (opens the fight already active)
  • Effect: At the start of your turn, put a random Attack from your Discard Pile into your hand — and it enters Upgraded for the rest of combat

The buff: what stacking means

Like all Ironclad Powers, Aggression stacks in intensity. Each stack pulls one more random Attack per turn: two stacks = two recycled attacks every turn, all upgraded. The buff is permanent for the combat, so an early Aggression compounds — the attacks it recycles get played, return to discard, and come back again next turn.

Why it's strong (and when it's not)

Strong when:

  • Your deck is Attack-dense — the more Attacks in discard, the better the odds the recycle lands on a payoff card (Bludgeon, Pommel Strike, Twin Strike chains).
  • You have discard-feeders — cards like Anger and Sword Boomerang refill the pile the same turn.
  • The fight is long — bosses and elites give the loop time to compound.

Weak when:

  • Your discard pile is empty or skill-heavy — recycling nothing is nothing.
  • The fight is over in two turns; the Power cost never pays itself back.

Decks that abuse it

  1. Strike-dense auto-attack: pair Aggression with Hellraiser — Strikes auto-play on draw, discard, and return upgraded.
  2. Strength stack: recycled upgraded Attacks carry your Strength scaling further than a 10-card rotation should allow.
  3. Exhaust-resistant loops: unlike Exhaust payoffs, Aggression never eats the Attack — it reprints it.

Aggression vs. the rest of the Ironclad pool

Where does it rank? S/A-borderline in our Ironclad card tier list — a Rare that asks one question (is my deck Attack-heavy?) and pays forever if the answer is yes.

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