Version

Synthesis

DefectAttackUncommon
Deal 14 damage.
The next Power you play costs 0 .

It hits for 14, 20 upgraded, then gives you a Free Power counter: the next Power you play from your hand costs 0. The counter has no timer, so it waits across turns until a Power is played, and repeated plays stack for more Powers. It only touches cards played from hand, not Powers auto-played by other effects.

Character
Defect
Type
Attack
Rarity
Uncommon
Cost
2 Energy
Target
One enemy

When to take Synthesis

Take it in a Defect with expensive Powers like Echo Form or Creative AI, since it pays for the next Power while also hitting. Upgrade it for the damage.

Cards that synergize with Synthesis

Echo Form
Power
3
Ethereal.
The first card you play each turn is played an extra time.
Echo Form and Creative AI are the 3-cost Powers it pays for.Ethereal.
The first card you play each turn is played an extra time.
Creative AI
Power
3
At the start of your turn, add a random Power into your Hand.
Echo Form and Creative AI are the 3-cost Powers it pays for.At the start of your turn, add a random Power into your Hand.
Subroutine
Power
1
Whenever you play a Power, gain .
Subroutine refunds a free Power into a gain.Whenever you play a Power, gain .
Storm
Power
1
Whenever you play a Power, Channel 1 Lightning.
Storm fires off the same play.Whenever you play a Power, Channel 1 Lightning.
Signal Boost
Skill
1
The next Power you play is played an additional time.
Exhaust.
Signal Boost doubles it.The next Power you play is played an additional time.
Exhaust.
Biased Cognition
Power
1
Gain 4 Focus.
At the start of your turn, lose 1 Focus.
Biased Cognition is a Power, and Synthesis triggers when you play oneGain 4 Focus.
At the start of your turn, lose 1 Focus.
Buffer
Power
2
Prevent the next time you would lose HP.
Buffer is a Power, and Synthesis triggers when you play onePrevent the next time you would lose HP.
Bulk Up
Power
2
Lose 1 Orb Slot.
Gain 2 Strength.
Gain 2 Dexterity.
Bulk Up is a Power, and Synthesis triggers when you play oneLose 1 Orb Slot.
Gain 2 Strength.
Gain 2 Dexterity.
Capacitor
Power
1
Gain 2 Orb Slots.
Capacitor is a Power, and Synthesis triggers when you play oneGain 2 Orb Slots.
Consuming Shadow
Power
2
Channel 2 Dark.
At the end of your turn, Evoke your leftmost Orb.
Consuming Shadow is a Power, and Synthesis triggers when you play oneChannel 2 Dark.
At the end of your turn, Evoke your leftmost Orb.
Coolant
Power
1
At the start of your turn, gain 2 Block for each unique Orb you have.
Coolant is a Power, and Synthesis triggers when you play oneAt the start of your turn, gain 2 Block for each unique Orb you have.
Defragment
Power
1
Gain 1 Focus.
Defragment is a Power, and Synthesis triggers when you play oneGain 1 Focus.
Feral
Power
2
The first time you play a
0 Attack each turn,
return it to your Hand.
Feral is a Power, and Synthesis triggers when you play oneThe first time you play a
0 Attack each turn,
return it to your Hand.
Hailstorm
Power
1
At the end of your turn, if you have Frost, deal 6 damage to ALL enemies.
Hailstorm is a Power, and Synthesis triggers when you play oneAt the end of your turn, if you have Frost, deal 6 damage to ALL enemies.
Iteration
Power
1
The first time you draw a Status each turn, draw 2 cards.
Iteration is a Power, and Synthesis triggers when you play oneThe first time you draw a Status each turn, draw 2 cards.
Loop
Power
1
At the start of your turn, trigger the passive ability of your rightmost Orb.
Loop is a Power, and Synthesis triggers when you play oneAt the start of your turn, trigger the passive ability of your rightmost Orb.
Machine Learning
Power
1
At the start of your turn, draw 1 additional card.
Machine Learning is a Power, and Synthesis triggers when you play oneAt the start of your turn, draw 1 additional card.
Smokestack
Power
1
Whenever you create a Status, deal 5 damage to ALL enemies.
Smokestack is a Power, and Synthesis triggers when you play oneWhenever you create a Status, deal 5 damage to ALL enemies.
Spinner
Power
1
At the start of your turn, Channel 1 Glass.
Spinner is a Power, and Synthesis triggers when you play oneAt the start of your turn, Channel 1 Glass.
Thunder
Power
1
Whenever you Evoke Lightning, deal 6 damage to each enemy hit.
Thunder is a Power, and Synthesis triggers when you play oneWhenever you Evoke Lightning, deal 6 damage to each enemy hit.
Trash to Treasure
Power
1
Whenever you create a Status, Channel 1 random Orb.
Trash to Treasure is a Power, and Synthesis triggers when you play oneWhenever you create a Status, Channel 1 random Orb.
Automation
Power
1
Every 10 cards you draw, gain .
Automation is a Power, and Synthesis triggers when you play oneEvery 10 cards you draw, gain .
Beacon of Hope
Power
1
Whenever you gain Block on your turn, other players gain half that much Block.
Beacon of Hope is a Power, and Synthesis triggers when you play oneWhenever you gain Block on your turn, other players gain half that much Block.
Calamity
Power
3
Whenever you play an Attack, add a random Attack into your Hand.
Calamity is a Power, and Synthesis triggers when you play oneWhenever you play an Attack, add a random Attack into your Hand.

Relics that synergize with Synthesis

Game Piece
Game Piece draws.Whenever you play a Power, draw 1 card.
Intimidating Helmet
Intimidating Helmet triggers on cards that cost 2 or more, and Synthesis is oneWhenever you play a card that costs or more, gain 4 Block.
✦
Storm
Power
1
Whenever you play a Power, Channel 1 Lightning.
Subroutine
Power
1
Whenever you play a Power, gain .
Signal Boost
Skill
1
The next Power you play is played an additional time.
Exhaust.

Changes by version

  1. 21 May 2026Damage12(18)14(20)Beta branch
    Damage increased from 12 to 14 (upgraded 18 to 20)
  2. 2 Apr 2026ArtBeta branch
    Added portrait art
  3. 20 Nov 2025Damage13(18)12(18)Internal playtest
    Damage decreased from 13 to 12
All 6 patch notes3 older
  1. 21 Aug 2025Damage12(18)13(18)Internal playtest
    Damage increased from 12 to 13
  2. 7 Aug 2025ArtInternal playtest
    Added beta portrait art
  3. 17 Jul 2025AddedInternal playtest
    Added to the game

Internal playtest notes are from before the Early Access release. Names and numbers in them can differ from the game today.

Purchase today
If you haven't bought Slay The Spire 2 yet, it's time. Support the devs, they made an amazing game.Get it on Steam