Coolant•Power

Is Coolant good in Slay the Spire 2?

Coolant is a rare Defect power in Slay the Spire 2. In combat it resolves as: At the start of your turn, gain 2 Block for each unique Orb you have. It currently underperforms most alternatives, sitting at D tier in our Slay the Spire 2 card rankings.

Across 39 recorded runs, decks running it win 22.9% of the time, comfortably clear of the 18.9% average, by 3.9%. It’s a more selective pick, turning up in just 1.0% of decks that could run it. Defect players keep it in 6.7% of their runs, so it’s a familiar sight in those decks. On average it shows up 1.0 times in the decks that take it.

It performs best next to TURBO — together they post a +16.4% swing in win rate. It also has strong chemistry with the relic Red Mask, which moves its win rate by +20.0%. At 1 energy, it’s upgraded in 15.4% of runs and usually joins the deck around floor 17.

That’s 8 wins, 27 deaths, and 4 abandoned runs with it in the deck. The encounter that most often ends a run carrying it is Queen Boss, which closes out 10.3% of its appearances. Read on for Coolant’s complete synergy, class, and threat breakdown to decide whether it earns a slot in your Defect run.

Best Cards to Pair with Coolant

Ranked by win-rate lift, Coolant performs best alongside TURBO (+16.4%), Flak Cannon (+14.9%), and Ice Lance (+14.1%).

TURBO+16.4%6 runsFlak Cannon+14.9%4 runsIce Lance+14.1%7 runsSubroutine+13.2%14 runsScrape+12.9%3 runsCold Snap+12.1%10 runs

Based on small co-occurring samples — treat these as early signals, not final verdicts.

Coolant Win Rate by Class

Coolant is drafted only by the Defect, where it holds a 22.9% win rate across 39 runs.

The Defectappears in 6.7% of its runs (39 tracked)

Best Relics for Coolant

Coolant pairs best with the relics Red Mask (+20.0%), Art of War (+17.8%), and Sturdy Clamp (+17.8%), ranked by win-rate lift.

Red Mask+20.0%7 runsArt of War+17.8%3 runsSturdy Clamp+17.8%3 runsCaptain's Wheel+14.9%4 runsVambrace+14.9%4 runsSmall Capsule+14.9%4 runs

Based on small co-occurring samples — treat these as early signals, not final verdicts.

Coolant Card Details

Coolant is a rare power costing 1 energy; it’s upgraded in 15.4% of runs and usually picked up by floor 17.

At the start of your turn, gain 2 Block for each unique Orb you have.

What Ends Runs with Coolant

Coolant’s most common run-enders are Queen Boss (10.3%), Kaiser Crab Boss (7.7%), and The Insatiable Boss (7.7%).

• Queen Boss10.3% of runs
• Kaiser Crab Boss7.7% of runs
• The Insatiable Boss7.7% of runs
• Ovicopter Normal5.1% of runs
• Test Subject Boss5.1% of runs

See Also

Compare Coolant with the rest of the best Slay the Spire 2 cards, relics, and classes below.