A Beginner’s Guide to Beating the Heart [Watcher Edition]

Basic Strategy for the Heart Fight

The fundamental principles for fighting the Heart, common to all characters, are:

・Be able to consistently generate at least 30 Block within 3 turns

・Prepare a high-damage attack as early as possible (the exact turn depends on your deck)

The Corrupt Heart gains Strength every few turns.

The longer the fight goes on, the more absurd the damage becomes, so chipping away won’t win you the fight.
Strength +50 is pure hell.

You need to burst it down with overwhelming damage.

Also, on turn 2, the Heart will either use a
“●×12 multi-hit attack” or a single massive hit.

It’s okay to take that turn-2 hit, even if it chunks your HP hard.

By that point, you should be setting up a situation where you can generate Block every turn or unleash massive damage.

Next, let’s look at specific tips for beating the Heart with the Watcher.

How to Beat the Heart with the Watcher

The core Watcher deck for Heart fights is the
“Wrath–Calm Switching” deck, centered around the uncommon card Tantrum.

What is a Wrath–Calm Switching Deck?

(Also known as: compressed Watcher, emotional instability deck, switching deck)

A deck that attacks repeatedly by frequently switching between Wrath, Calm, and no stance.

Because it requires planning ahead each turn, it’s better suited for players familiar with the Watcher,
but it boasts the highest win rate and is the easiest to assemble (according to the author).

It is also commonly used even in the highest difficulty mode (Ascension 20) Heart fights.

While the Watcher has many possible archetypes like other characters,
the Tantrum-based switching deck is overwhelmingly powerful.

Compared to any deck archetype across all characters,
it stands out as the strongest when considering both power and ease of construction.

Highly recommended for the Heart fight.

Core Key Cards for the Switching Deck

First, let’s introduce the key cards.

Beginner-friendly key cards include:

・Attack cards: Windmill Strike, Flurry of Blows

・Stance cards: Tantrum, Meditate, the “Empty ○○” series (and Blasphemy if available)

・Block cards: Mental Fortress, retain-based blocks (Perseverance, Protect, etc.)

For detailed explanations of each card, please refer to:
Watcher | Card Tier List & Full Card Guide

Next, we’ll explain how to actually play the switching deck.

Basic Gameplay for the Switching Deck

Here’s how the switching deck works:

Sources of damage ▼

・Tantrum
・Flurry of Blows, which returns to your hand when changing stance
・Windmill Strike while in Wrath stance
（If you have Blasphemy, Windmill Strike in Divinity stance can be your finisher）

Block ▼

・Block gained from stance changes (Mental Fortress)
・Emergency retain blocks (Perseverance, Protect)

How to repeatedly switch stances ▼

Pick Calm stance cards, stance exit cards, and Wrath stance cards.

Recommended ratio of switching cards in the deck ▼

Calm : Stance Exit : Wrath = 3 : 3 : 2

・3 Calm stance cards
・2–3 stance exit cards (including the “Empty ○○” series)
・2–3 Wrath stance cards (Tantrum + Eruption)

Deck example (beginner-friendly) ▼

This sample deck follows the guidelines above.

An easy clear with only 6 damage taken over 8 turns in the Heart fight.

Flurry of Blows, Windmill Strike, and Sands of Time (retain attack) are the main damage sources.

Mental Fortress serves as the main Block engine, supplemented with retain-based blocks.

Upgraded Blasphemy is kept in hand at all times and used as a finisher.

The Heart-fight MVP relic “Tungsten Rod” also shines here.

For a first Heart clear, the switching deck is strongly recommended—
but in truth, the Watcher can clear the Heart with many archetypes.

As a reference, next we introduce the “Pressure Points” deck,
which doesn’t use stances at all.

Bonus: Beating the Heart with a “Pressure Points” Deck

First, a disclaimer.

The Pressure Points deck introduced here is:

Not a deck particularly suited for the Heart fight.

However, when it comes together, it feels amazing to play,
so it’s definitely an archetype worth trying.

What is a Pressure Points deck? ▼

A deck centered around the common card “Pressure Points”.

Each time you apply Pressure Points to an enemy, the damage stacks.

Its playstyle is similar to the Silent’s poison deck
(reference:
Silent | Tips & Standard Deck Guides).

After applying Pressure Points to one enemy and then another:

・First enemy: 16 damage (22 when upgraded)
・Second enemy: 8 damage (11 when upgraded)

This effectively functions as pseudo-AoE damage—very convenient.

By leveraging draw and scry,
the key is how quickly you can apply Pressure Points repeatedly.

Key Cards & How to Play the Pressure Points Deck

Key cards include:

・Pressure Points (at least 2; 5 makes it very stable)
・Third Eye (and other scry cards)
・Meditate
・Empty Mind
・Nirvana

Gameplay revolves around repeatedly reusing Pressure Points while stacking Block via three main combos:

・Compress the deck with Third Eye
・Use Meditate to retain next-turn essentials
(priority: Empty Mind = Pressure Points > Third Eye)
・Stay in Calm stance as much as possible, drawing and generating energy with Empty Mind
・Stack Block with Nirvana

Deck example ▼

An ideal Pressure Points deck.

Stack Block and Pressure Points through scry,
stall turns with Leap, and generate energy with Collect.

Meditate and Empty Mind provide draw and energy.

A finisher was found in Act 1 and used for hallway fights.

The end.

◆ Watcher-related Articles ◆

Watcher | Tips & Standard Deck Guides

Watcher | Card Tier List & Full Card Guide

Watcher | Winning Deck Examples

Watcher | Explained Picks Across 50 Floors

World Rank #1 | Watcher Longest Win Streak Decks