Ironclad Vulnerable Aggro Build — Dismantle, Cruelty & Colossus Guide

The Vulnerable Aggro build is the Ironclad’s most straightforward archetype — and arguably the strongest for new players climbing early ascensions. The game plan is dead simple: apply Vulnerable (enemies take 50% more damage), then cash in with attacks that get bonus effects against Vulnerable targets. There’s no multi-turn setup, no fragile combo pieces, no “draw your whole deck” shenanigans. Just hit them hard, hit them while they’re vulnerable, and watch health bars evaporate.

The build’s Secret Weapon is Cruelty — a rare Power that makes Vulnerable enemies take an ADDITIONAL 25-50% damage. Stacked with the base 50% Vulnerable multiplier, your attacks deal nearly double damage. Dismantle hits twice. Colossus keeps you alive. It’s the Ironclad distilled to its purest form.

Build Overview

The Vulnerable Aggro game plan: apply Vulnerable early → amplify with Cruelty → Burst with Dismantle double-hits → Defend with Colossus against counterattacks. Fights end fast because your damage output is so high that enemies don’t get a second attack cycle. This is the build for players who hate waiting for Demon Form to ramp up.

Vulnerable Aggro

beginnerIronclad

Core Cards

Dismantle

Cruelty

Colossus

Bash

Uppercut

Tremble

Dominate

Key Relics

Paper PhrogBag of MarblesHand DrillUnsettling LampRed Skull

Strategy

Apply Vulnerable on turn 1 (Bash or Bag of Marbles). Play Cruelty as soon as drawn — it's your win condition. Use Dismantle for 20 damage per energy against Vulnerable targets. Defend with Colossus when enemies counterattack. Against bosses, stack Dominate for Strength scaling and finish with multi-hit attacks. Build ends fights in 3-5 turns — faster than Strength or Exhaust builds.

Core Cards — What to Pick and Why

S-Tier: The Cards That Define the Build

Bash — Your starting card is your first Vulnerable source. Deal 8 damage, apply 2 Vulnerable. At 2 energy it’s expensive, but it’s also your turn-1 play in every fight until you find better sources. Upgrade it early (8→11 damage) if you haven’t found a replacement Vulnerable applier by the first campfire. Once you have Tremble or Uppercut, Bash becomes a backup — don’t remove it, but don’t prioritize upgrading it either.

Pick priority: Already in your deck. Upgrade by first campfire if no better Vulnerable source found.

Dismantle — Deal 8 damage (10 upgraded). If the enemy is Vulnerable, hits TWICE. That’s 16-20 damage for 1 energy — the best damage-per-energy ratio in the Ironclad pool. A single upgraded Dismantle on a Vulnerable target deals 20 damage. Two Dismantles = 40 damage for 2 energy. Three = 60 damage. This card IS your damage engine. Take every copy you see (2-3 is ideal). Upgrade all of them.

Pick priority: Take on sight. This is the card that makes the Vulnerable archetype work. Without Dismantle, you’re just applying a debuff with no payoff.

Cruelty — Vulnerable enemies take an additional 25% damage (50% upgraded). This stacks multiplicatively with the base Vulnerable debuff. The math: base damage × 1.5 (Vulnerable) × 1.5 (Cruelty+) = 2.25× damage. Your 20-damage Dismantle now hits for 45. Your 30-damage Uppercut hits for 67. Cruelty turns the Vulnerable build from “efficient” to “unfair.” Take 1-2 copies. Upgrade immediately — the jump from 25% to 50% doubles Cruelty’s effectiveness.

Pick priority: Highest priority rare. If you see Cruelty in a shop, buy it. If you see it as a card reward, take it over everything except a second Dismantle.

Colossus — Gain 5 Block (8 upgraded). You take 50% less damage from Vulnerable enemies this turn. This solves the Vulnerable build’s biggest weakness: you’re so focused on damage that you forget to block. Against an enemy with 3×8 attacks (24 total), Colossus reduces that to 12, and your 5 Block covers almost all of it. Against the Champ’s Execute (60 damage), Colossus cuts it to 30, and your 8 Block handles a quarter of that before other block cards.

Pick priority: Take 1-2 copies by Act 2. Not needed in Act 1 if you’re killing enemies in 2 turns, but essential for elites and bosses.

A-Tier: The Engine Builders

Tremble — Apply 1 Vulnerable to ALL enemies at the start of each turn for 3 turns (upgraded: 4 turns + 2 Vulnerable per turn). This is your set-and-forget Vulnerable engine. Play it once and every enemy is Vulnerable for the rest of the fight. In multi-enemy rooms, Tremble saves you 3-4 energy you would have spent applying Vulnerable individually. It’s also your best answer to the Awakened One’s cultists and Donu & Deca.

Uppercut — Deal 13 damage, apply 1 Weak + 1 Vulnerable (upgraded: 13→16 damage, 1→2 Weak, 1→2 Vulnerable). The Ironclad’s Swiss Army knife. Uppercut does three things: deals solid damage, applies your key debuff (Vulnerable), AND applies Weak (enemies deal 25% less damage). In a single card, you advance your game plan AND your defense. This is often the card that carries Act 1 elite fights.

Dominate — Gain 1 Strength for each stack of Vulnerable on the target (upgraded: 2 Strength per stack). Against bosses where you’re stacking 5-10 Vulnerable, Dominate grants 5-20 Strength in one play. At 10 Strength, even your basic Strikes hit for 16. Pair with multi-hit attacks (Twin Strike, Sword Boomerang) for massive Burst turns.

Vicious — Draw 1 card every time you apply Vulnerable. With Tremble applying Vulnerable every turn and Uppercut/Dismantle applying it on play, Vicious turns your debuff engine into a card draw engine. In a deck with 4-5 Vulnerable sources, Vicious draws 3-5 extra cards per fight — better than a free Battle Trance.

B-Tier: The Workhorses

Taunt — Apply 1 Vulnerable to ALL enemies, gain 7 Block. Cloak and Dagger for the Ironclad — it simultaneously advances your game plan and your defense. Excellent Act 1 pick because it solves two problems at once.

Molten Fist — Deal 8 damage, apply 2 Vulnerable. Simple, efficient, reliable. Better than Bash because it costs 1 energy instead of 2. Take 1 copy in Act 1 if you need more Vulnerable sources.

Twin Strike — Deal 5 damage twice. With Vulnerable (+50%) and Cruelty (+50%), each hit deals 11 damage — 22 total for 1 energy. The multi-hit nature also benefits from Strength (Dominate). Take 1-2 copies as supplementary damage.

Sword Boomerang — Deal 3 damage to a random enemy 3 times. At 1 energy, this is 9 base damage that scales 3× with Strength and benefits 3× from Vulnerable. With 5 Strength + Vulnerable + Cruelty, each hit deals 12 → 36 total for 1 energy. Excellent against single targets.

Cards to AVOID

• Demon Form: Wrong archetype. You want fights to end in 3-4 turns, not ramp for 6 turns. Demon Form costs 3 energy for zero immediate impact — the opposite of what this build wants.
• Barricade: You’re not building a block wall. Fights end too fast for Block retention to matter.
• Entrench: Same reason. Your block exists to buy time while Dismantle kills things, not as a win condition.
• Corruption: Exhaust engine belongs in a different deck. You play Skills for their immediate value, not to thin your deck.

Relic Priority

Run-Defining

• Paper Phrog: Vulnerable enemies take 75% more damage instead of 50%. Stacked with Cruelty+, that’s base × 1.75 × 1.5 = 2.625× damage. Dismantle now hits for 52. This relic alone wins runs.
• Bag of Marbles: Apply 1 Vulnerable to ALL enemies at combat start. Free turn-1 Vulnerable without spending energy or a card. With this + Cruelty in play, Dismantle hits for double on turn 1.

High Impact

• Hand Drill: Apply 2 Vulnerable whenever you Break an enemy’s Block. Turns Block-Breaking from a tempo loss into a debuff opportunity. Premium against Shelled Parasite, Snake Plant, and The Guardian.
• Unsettling Lamp: First debuff each combat is doubled. Your turn-1 Uppercut now applies 4 Vulnerable + 4 Weak instead of 2+2. Or Tremble applies 6 Vulnerable over 3 turns instead of 3.
• Red Skull: +3 Strength below 50% HP. The Vulnerable build trades HP aggressively in Act 1. Red Skull rewards that playstyle by making you hit harder when you’re low — exactly when you need to end fights fastest.

Nice to Have

• Vajra: Start combat with +1 Strength. Free damage on every attack — especially valuable on Dismantle’s double-hit.
• Brimstone: +2 Strength per turn for everyone. The Vulnerable build kills fast enough that the enemy’s Strength rarely matters. You kill them before they can use it.
• Anchor: Start combat with 10 Block. Lets you spend turn 1 playing Cruelty instead of blocking. The tempo gain is enormous.

Act-by-Act Strategy

Act 1 — Establish the Vulnerable Engine

Your turn-1 play in every Act 1 fight should be: Bash → apply Vulnerable, then attack. That’s the core Loop.

Floor 1-5 priorities:

1. Dismantle — Always take. Your win condition.
2. Uppercut — Damage + Vulnerable + Weak. Perfect Act 1 card.
3. Taunt — Block + Vulnerable. Solves two problems.
4. Tremble — Premium against Sentries and Slime Boss.
5. Twin Strike / Sword Boomerang — Multi-hit attacks for damage.

Fight 2-3 elites in Act 1. The Vulnerable build excels against elites because they’re single targets with high HP — exactly what Dismantle punishes:

• Sentries (Easy): Bash one, Dismantle for 20. Next turn, Bash another, Dismantle again. You kill one Sentry per turn.
• Lagavulin (Favorable): Wake-up turn: Uppercut for Vulnerable + Weak. Next turn: Dismantle for double damage. The Weak from Uppercut reduces its 18-damage hits to 13.
• Gremlin Nob (DAngerous): You play Skills (Bash, Uppercut) which give it Strength. But you also kill it in 3 turns because Vulnerable + Dismantle deals so much damage. If your first 3 card picks have 2+ attacks, take this fight.

Campfire priority:

1. Upgrade Dismantle (8→10 damage, 16→20 on double-hit)
2. Upgrade Bash if it’s your only Vulnerable source
3. Upgrade Uppercut (13→16 damage + 1→2 Weak/Vulnerable)

Act 2 — Add Scaling and Defense

By Act 2 you should have 2-3 Dismantles, 2-3 Vulnerable sources, and at least 1 defensive card. Now hunt for Cruelty and Colossus.

Priority picks:

1. Cruelty — Hunt at shops. This is the card that keeps your damage relevant in Act 2-3.
2. Colossus — You need defense. Act 2 hallway fights hit hard (Shelled Parasite, Snake Plant).
3. Dominate — Strength scaling for boss fights.
4. Vicious — Card draw engine.

Elite strategy:

• Tri-Slavers (Medium): Tremble applies Vulnerable to all three. Focus the red Slaver first. Dismantle kills each in 2 turns.
• Book of Stabbing (Hard): Colossus is essential — reduces multi-hit damage by 50%. Uppercut’s Weak stacks with Colossus for massive damage reduction.
• Gremlin Leader (Favorable): Dismantle kills minions in one hit. Tremble keeps Vulnerable on the Leader while you clear adds.

Act 3 — Refine and Execute

Your deck should be 20-25 cards with: 2-3 Dismantle, 1-2 Cruelty, 1-2 Colossus, 2-3 Vulnerable sources, 4-5 block cards.

Final boss strategy:

• Time Eater (Medium): 12-card limit means you can’t spam. Make every card count. One Dismantle per turn + one block card. Cruelty must be in play early.
• Awakened One (Favorable): Cruelty is a Power, which gives it Strength — but you kill it so fast it doesn’t matter. Kill cultists first, then Dismantle chain the boss.
• Donu & Deca (Favorable): Tremble hits both. Focus Donu. Colossus handles their multi-hit attacks. Dismantle kills Donu in 3-4 turns, then Deca is cleanup.

Key Tips

1. Vulnerable FIRST, damage SECOND. Never play Dismantle before applying Vulnerable. The difference is 8 damage vs. 16 (or 10 vs. 20 upgraded). Patience is rewarded.

2. Cruelty IS your scaling. Where Strength builds have Demon Form and Exhaust builds have Dark Embrace, you have Cruelty. Without it, your damage falls off in Act 3. Hunt it aggressively.

3. Keep the deck lean. 20-25 cards. Every non-Vulnerable, non-attack card dilutes your Dismantle draws. Remove Strikes at shops — your attacks should be Dismantle, Uppercut, and Twin Strike.

4. Don’t neglect block. The most common way this build dies: drawing 5 attacks and 0 block against an enemy attacking for 30. Aim for 5-7 block cards by Act 3.

5. Upgrade Dismantle FIRST. The jump from 8→10 base damage compounds across the double-hit (16→20). If you have 3 Dismantles, upgrading all three is +12 damage per Dismantle cycle. That wins runs.

Matchup Guide

Favorable: Slime Boss (Tremble hits all slimes), The Champ (Dismantle Bursts before Execute), Donu & Deca (Tremble + multi-hit attacks), Sentries (Dismantle one-shots), Gremlin Leader (Dismantle clears minions)

Unfavorable: Time Eater (card limit restricts Dismantle spam), Book of Stabbing (multi-hits demand perfect block timing), Gremlin Nob (Skill-heavy deck triggers its Strength gain)

Nemesis: The Corrupted Heart. Beat of Death (2 damage per card) punishes your multi-attack playstyle. Colossus + Uppercut’s Weak are mandatory. You need 30+ block on turn 3.