Rainbow•Skill

Is Rainbow good in Slay the Spire 2?

Rainbow is a rare Defect skill in Slay the Spire 2. In combat it resolves as: Channel 1 Lightning. Channel 1 Frost. Channel 1 Dark. It currently underperforms most alternatives, sitting at D tier in our Slay the Spire 2 card rankings.

Across 43 recorded runs, decks running it win 24.3% of the time, comfortably clear of the 18.9% average, by 5.4%. It’s a more selective pick, turning up in just 1.1% of decks that could run it. Defect players keep it in 7.4% of their runs, so it’s a familiar sight in those decks. On average it shows up 1.1 times in the decks that take it.

It performs best next to White Noise — together they post a +11.9% swing in win rate. It also has strong chemistry with the relic Oddly Smooth Stone, which moves its win rate by +18.6%. At 2 energy, it’s upgraded in 24.4% of runs and usually joins the deck around floor 17.

That’s 9 wins, 28 deaths, and 6 abandoned runs with it in the deck. The encounter that most often ends a run carrying it is Queen Boss, which closes out 14.0% of its appearances. Read on for Rainbow’s complete synergy, class, and threat breakdown to decide whether it earns a slot in your Defect run.

Best Cards to Pair with Rainbow

Ranked by win-rate lift, Rainbow performs best alongside White Noise (+11.9%), Echo Form (+11.4%), and Squash (+9.8%).

White Noise+11.9%8 runsEcho Form+11.4%9 runsSquash+9.8%3 runsMachine Learning+9.8%3 runsGlacier+9.8%4 runsModded+9.8%4 runs

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

Rainbow Win Rate by Class

Rainbow is drafted only by the Defect, where it holds a 24.3% win rate across 43 runs.

The Defectappears in 7.4% of its runs (43 tracked)

Best Relics for Rainbow

Rainbow pairs best with the relics Oddly Smooth Stone (+18.6%), Regal Pillow (+17.0%), and Red Mask (+15.9%), ranked by win-rate lift.

Oddly Smooth Stone+18.6%6 runsRegal Pillow+17.0%9 runsRed Mask+15.9%6 runsParrying Shield+14.5%4 runsHappy Flower+13.5%7 runsPen Nib+11.9%5 runs

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

Rainbow Card Details

Rainbow is a rare skill costing 2 energy; it’s upgraded in 24.4% of runs and usually picked up by floor 17.

Channel 1 Lightning. Channel 1 Frost. Channel 1 Dark.

What Ends Runs with Rainbow

Rainbow’s most common run-enders are Queen Boss (14.0%), Kaiser Crab Boss (9.3%), and Lagavulin Matriarch Boss (4.7%).

• Queen Boss14.0% of runs
• Kaiser Crab Boss9.3% of runs
• Lagavulin Matriarch Boss4.7% of runs
• Decimillipede Elite4.7% of runs
• The Insatiable Boss4.7% of runs

See Also

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