Ironclad Corruption Exhaust Build: The Immortal Block Engine

The Corruption Exhaust build is Ironclad's strongest A20 archetype — and arguably the most powerful build in all of Slay the Spire 2. By chaining exhaust synergies, you generate infinite block, infinite card draw, and infinite damage, all while naturally thinning your deck mid-combat. This is the build that veteran players use to climb Ascension levels consistently.

1. How It Works

The engine has three pillars that feed each other:

With all three online, every Skill you play: costs 0 → grants Block → draws a card → which might be another Skill → repeat. You can play your entire skill deck in a single turn while gaining hundreds of Block. Meanwhile, your deck self-thins, leaving only attacks that you draw every turn.

The beauty of this build is that it scales into itself. Every exhausted card makes your deck smaller, which makes you draw your remaining cards more often, which accelerates the engine further. By turn 4-5 of a boss fight, your 25-card deck becomes a 10-card machine that you cycle every single turn.

2. Core Cards

Must-Have (S-Tier)

• Corruption — The keystone. Once played, your entire skill suite becomes free. Upgrade reduces cost from 3 to 2 — essential at high Ascension where turn 1 is critical.
• Feel No Pain — Converts exhaust into block. With Corruption, a single Defend now gives 3-4 extra Block on top. Stack 2-3 copies for 9-12 Block per exhaust.
• Dark Embrace — Converts exhaust into card draw. With 2 Dark Embraces in play, one Shrug It Off becomes: 0 cost → 8 Block + 4 from FNP → draw 1 + 2 from Dark Embrace → 3 cards total.
• Body Slam — 0 cost, deal damage equal to your current Block. When you have 100+ Block (which you will), this one-shots everything. The build's primary win condition.

Strong Support (A-Tier)

• Shrug It Off — 0-cost Block + draw under Corruption. The perfect skill for this engine.
• Impervious — 30-40 Block for 0 cost. With FNP, that's 34-44 Block and draws 1-2 cards.
• Offering — 0-cost energy + card draw. Kicks off the engine on turn 1. The best setup card in the game.
• Second Wind — Exhaust all non-Attack cards in hand, gain Block per card exhausted. Underpowered alone, but with FNP + Dark Embrace, it's a huge block + draw burst.
• Battle Trance — 0-cost draw 3-4. Helps find Corruption on turn 1-2.
• True Grit+ — Block + targeted exhaust. Use it to remove Strikes mid-combat, accelerating the engine.

Defensive Foundation

• Disarm — 0-cost under Corruption. Shuts down multi-hit enemies entirely.
• Flame Barrier — Block + thorns for 0 cost. Excellent against Book of Stabbing and Byrds.
• Ghostly Armor — Efficient block that becomes free under Corruption.
• Shockwave — AoE Weak + Vulnerable. Free under Corruption, devastating with Body Slam follow-up.

3. Best Relics

• Dead Branch (S+) — When a card exhausts, add a random card to your hand. With Corruption making everything exhaust, this floods your hand with free skills every turn. The single strongest relic for this build — it turns a controlled engine into absolute chaos in the best way.
• Charon's Ashes (S) — Deal 3 damage to ALL enemies whenever you exhaust a card. In a Corruption deck that exhausts 10+ cards per turn, that's 30+ AoE damage passively.
• Snecko Eye (A) — +2 card draw, randomizes costs. Corruption ignores cost randomization for Skills, so you get the draw bonus for free. Less essential than in Strength builds but still strong.
• Medical Kit (A) — Exhaust status cards. Turns Wounds and Dazes into block and draw engines.
• Calipers (A) — Lose only 15 Block at turn start instead of all. With FNP generating 50+ Block per turn, Calipers lets you carry over hundreds of Block between turns.
• Mummified Hand (B) — A Power played makes a random card cost 0. Nice early-game but redundant once Corruption is online.

4. Run Strategy — Stage by Stage

1. Floors 1-8 (Early Act 1):

   Play like a standard Ironclad. Take attacks — Carnage, Hemokinesis, Anger. You need damage to clear Act 1 elites. If you see Feel No Pain or Shrug It Off, grab them — they're functional even without Corruption. Don't take Corruption yet unless you have at least 3 skills to support it.

2. Floors 9-16 (Late Act 1):

   If offered Corruption, take it. But do not play it in hallway fights — it will exhaust all your block skills and leave you defenseless. Save it for elites and bosses. Look for Dark Embrace and a second Feel No Pain. Start removing Strikes at shops.

3. Floors 17-25 (Early Act 2):

   This is the build's power spike. With Corruption + 1 FNP + 1 Dark Embrace, you can beat any Act 2 fight without taking damage. Stack block skills aggressively — Shrug It Off, True Grit, Ghostly Armor. Take Body Slam whenever you see it. At this point, every skill pickup is a direct power increase.

4. Floors 26-33 (Late Act 2):

   Refine your setup. Upgrade Corruption (3→2 cost) and Dark Embrace (2→1 cost) at campfires. If you found Exhume, the build is now capable of infinite loops. Remove remaining Strikes. Your deck should be 20-25 cards with ~15 being skills.

5. Floors 34-50 (Act 3):

   Turn 1: play Corruption + Feel No Pain + Dark Embrace. Turn 2+: every skill is free, drawing cards and generating block. Stack Body Slam when block exceeds 100. Against bosses, you'll typically have 200+ Block by turn 5, at which point Body Slam one-shots anything. You are effectively unkillable.

5. Matchup Notes

• vs Sentries (Act 1 Elite): Dazed cards trigger FNP + Dark Embrace. Sentries fill your deck with Dazed, which you then exhaust for free block and draw — they're actually helping you. Easiest elite matchup.
• vs Slime Boss: Play Corruption after the first split. Exhausted skills thin your deck while generating block. Body Slam kills each split in one hit.
• vs Book of Stabbing (Act 2 Elite): Multi-hit is meaningless when you generate 40+ Block per turn. Disarm reduces each hit to 1-2 damage. Trivial.
• vs Time Eater: Your card count matters. Each skill play counts toward the 12-card limit. Plan your bursts — play 10-11 skills, let the turn end, Body Slam on the next turn. Not your hardest matchup, but requires planning.
• vs Awakened One: Before he transforms, play only 1-2 Powers (Corruption + FNP). Save Dark Embrace for phase 2. He clears debuffs but not powers on transform.

6. Exhaust vs. Strength: Which to Pick?

For A20 climbing and consistent wins, the Exhaust build is superior. For learning the game or speed running lower Ascension levels, Strength is more forgiving. Both builds share enough cards that you can pivot between them mid-run if the right pieces show up.

Also check: Ironclad Strength Build · Card Database · Infinite Combos Guide