Flash of Steel•Attack

Is Flash of Steel good in Slay the Spire 2?

Flash of Steel is an uncommon Colorless attack in Slay the Spire 2. In combat it resolves as: Deal 5 damage. Draw 1 card. It’s a dependable, middle-of-the-pack option, landing at C tier in our rankings.

Across 194 recorded runs, decks running it win 25.6% of the time, comfortably clear of the 13.9% average, by 11.7%. It’s a more selective pick, turning up in just 1.7% of decks that could run it. Offer data is close to a wash — 8.9% of offers taken, 25.5% for runs that picked it against 24.9% for runs that skipped, a pick lift of just +0.5% over 51 decided runs. Regent players keep it in 1.1% of their runs, so it’s a familiar sight in those decks. On average it shows up 1.4 times in the decks that take it.

It performs best next to Armaments — together they post a +9.8% swing in win rate. It also has strong chemistry with the relic Blood Vial, which moves its win rate by +23.3%. At 0 energy, it’s upgraded in 9.2% of runs and usually joins the deck around floor 18.

Upgraded, it gains +3 Damage, which is why so many decks invest a rest-site upgrade in it. That’s 49 wins, 142 deaths, and 3 abandoned runs with it in the deck. The encounter that most often ends a run carrying it is Queen Boss, which closes out 7.2% of its appearances. Read on for Flash of Steel’s complete synergy, class, and threat breakdown to decide whether it earns a slot in your Colorless run.

Pick or Skip: Flash of Steel

Out of 586 recorded offers Flash of Steel is taken 8.9% of the time, and taking it is worth +0.5% in pick lift — 25.5% for runs that picked it against 24.9% for runs that skipped, across 51 decided runs.

Taken 52 times out of 586 offers.

Pick rate when offered counts offers, not runs: out of every time the game put this in front of a player, how often it was taken. It is not the same number as the share of runs that end up containing it.

Pick lift is the sample-adjusted gap between runs that took the option and runs that passed on it. It is the fair way to rank choices, because raw win rates put the smallest samples on top.

When to Pick Up Flash of Steel

Flash of Steel is strongest when it joins the deck in Act 3, where runs win 54.8% across 32 runs — one of 3 recorded pickup windows.

Win rate of runs by the act Flash of Steel entered the deck. Acts that have not reached the sample floor show their run count only.

Best Cards to Pair with Flash of Steel

Ranked by win-rate lift, Flash of Steel performs best alongside Armaments (+9.8%), Glow (+8.6%), and Mad Science (+8.6%).

Armaments+9.8%17 runsGlow+8.6%16 runsMad Science+8.6%15 runsDagger Throw+8.6%15 runsAcrobatics+8.5%18 runsPommel Strike+8.3%28 runs

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

Flash of Steel Win Rate by Class

Flash of Steel is played across 5 classes, led by Regent (30.0%), Ironclad (28.3%), and Silent (28.3%) by win rate.

The Regent30.0%21 runsThe Ironclad28.3%54 runsThe Silent28.3%47 runsThe Defect21.2%33 runsThe Necrobinder18.4%38 runs

Best Relics for Flash of Steel

Flash of Steel pairs best with the relics Blood Vial (+23.3%), Mercury Hourglass (+22.9%), and Akabeko (+22.8%), ranked by win-rate lift.

Blood Vial+23.3%31 runsMercury Hourglass+22.9%21 runsAkabeko+22.8%19 runsRegal Pillow+20.9%33 runsLetter Opener+20.9%18 runsVenerable Tea Set+20.8%31 runs

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

Flash of Steel Card Details

Flash of Steel is an uncommon attack costing 0 energy; it’s upgraded in 9.2% of runs and usually picked up by floor 18.

Deal 5 damage. Draw 1 card.

Upgrade: +3 Damage

What Ends Runs with Flash of Steel

Flash of Steel’s most common run-enders are Queen Boss (7.2%), Knowledge Demon Boss (6.2%), and Decimillipede Elite (4.6%).

• Queen Boss7.2% of runs
• Knowledge Demon Boss6.2% of runs
• Decimillipede Elite4.6% of runs
• Aeonglass Boss4.6% of runs
• Kaiser Crab Boss4.1% of runs

See Also

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