Symbiotic VirusRelic
At the start of each combat, Channel Dark.
Is Symbiotic Virus good in Slay the Spire 2?
In Slay the Spire 2, Symbiotic Virus is an uncommon relic you can pick up on your climb. Its effect: At the start of each combat, Channel Dark. The data marks it as a weaker relic, settling at D tier — rarely a run-defining grab.
Over 23 tracked runs the win rate of decks holding it sits at 28.6%, 9.6% ahead of the 19.0% all-run baseline. It sees lighter play, carried in only 0.6% of runs. It does its best work in the hands of the Defect, who post a 28.6% win rate with it. Within Defect runs specifically, it’s carried 3.9% of the time.
Its standout card pairing is Supercritical, which lifts the relic’s win rate by +71.4% when both are in play. It also works nicely with Compact, good for a +71.4% win-rate change. It typically enters the deck near floor 19. As an uncommon relic, how often it’s offered depends on its rarity tier.
Of the runs that carried it, 6 ended in victory while 15 fell to a defeat. Its most common run-ender is Test Subject Boss, finishing 13.0% of the runs it appears in. See the best cards, class split, and threats below for the full read on whether Symbiotic Virus is worth grabbing.
Symbiotic Virus Win Rate & Pick Rate
At a 28.6% win rate, Symbiotic Virus runs 9.6% ahead of the 19.0% all-run baseline — the bars below put the two side by side.
Run Outcomes with Symbiotic Virus
Across the 23 runs that carried Symbiotic Virus, 6 ended in a win and 17 in a loss — a 26.1% win share, counting abandons as losses.
- Wins 26.1%
- Losses 73.9%
Best Cards with Symbiotic Virus
The cards that gain the most from carrying Symbiotic Virus are Supercritical (+71.4%), Compact (+71.4%), and Overclock (+71.4%), each shown with its win-rate swing.
Based on small co-occurring samples — treat these as early signals, not final verdicts.
Symbiotic Virus Win Rate by Class
Symbiotic Virus’s class data comes mostly from the Defect, at a 28.6% win rate over 23 runs.
The Defectappears in 3.9% of its runs (23 tracked)Symbiotic Virus Details
Carried in 0.6% of runs, Symbiotic Virus is an uncommon relic typically acquired near floor 19.
At the start of each combat, Channel Dark.
What Ends Runs with Symbiotic Virus
Runs carrying Symbiotic Virus end most often against Test Subject Boss (13.0%) and Kaiser Crab Boss (8.7%) — the share of its runs each accounts for is shown.
- Test Subject Boss13.0% of runs
- Kaiser Crab Boss8.7% of runs
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Symbiotic Virus – Frequently Asked Questions
Is Symbiotic Virus good in Slay the Spire 2?
Across 23 tracked runs carrying it, Symbiotic Virus wins 28.6% of the time — +9.6% above the average run. Win rate reflects how often runs with the relic end in victory.
What does Symbiotic Virus do in Slay the Spire 2?
At the start of each combat, Channel Dark.
How rare is Symbiotic Virus in Slay the Spire 2?
Symbiotic Virus is an Uncommon relic, picked up in 0.6% of tracked runs.
What is the best card to use with Symbiotic Virus?
In tracked runs, Symbiotic Virus has performed best alongside Supercritical, which lifts its win rate by +71.4% over 4 runs together.
See Also
Keep exploring Slay the Spire 2 tier lists and stats below.