Confidence:StrongSolidPlausibleTentativeSpeculative

• Voltaic Key

  1

  ArtifactC

  One-directional refresh: one card can untap permanents the other wants to reuse. Not self-sustaining on its own — the untapper has to keep showing up.
• Intellectual Offering

  4U

  InstantU

  Intellectual Offering untaps all (or many) permanents, refreshing Serum Powder's tap activation.
• Unstoppable Plan

  2U

  EnchantmentU

  Unstoppable Plan untaps all (or many) permanents, refreshing Serum Powder's tap activation.
• Manifold Key

  1

  ArtifactC

  One-directional refresh: one card can untap permanents the other wants to reuse. Not self-sustaining on its own — the untapper has to keep showing up.
• Captain of the Mists

  2U

  Creature — Human WizardU

  One-directional refresh: one card can untap permanents the other wants to reuse. Not self-sustaining on its own — the untapper has to keep showing up.
• Sonic Screwdriver

  3

  ArtifactC

  One-directional refresh: one card can untap permanents the other wants to reuse. Not self-sustaining on its own — the untapper has to keep showing up.
• Galvanic Key

  2

  ArtifactC

  One-directional refresh: one card can untap permanents the other wants to reuse. Not self-sustaining on its own — the untapper has to keep showing up.
• Seedborn Muse

  3GG

  Creature — SpiritG

  Seedborn Muse untaps all (or many) permanents, refreshing Serum Powder's tap activation.
• Unwinding Clock

  4

  ArtifactC

  Unwinding Clock untaps all (or many) permanents, refreshing Serum Powder's tap activation.
• Paradox Engine

  5

  Legendary ArtifactC

  Paradox Engine untaps all (or many) permanents, refreshing Serum Powder's tap activation.
• Filigree Sages

  3U

  Artifact Creature — Vedalken WizardU

  One-directional refresh: one card can untap permanents the other wants to reuse. Not self-sustaining on its own — the untapper has to keep showing up.
• Elder Druid

  3G

  Creature — Elf Cleric DruidG

  One-directional refresh: one card can untap permanents the other wants to reuse. Not self-sustaining on its own — the untapper has to keep showing up.
• The Pandorica

  2W

  Legendary ArtifactW

  One-directional refresh: one card can untap permanents the other wants to reuse. Not self-sustaining on its own — the untapper has to keep showing up.
• Dramatic Reversal

  1U

  InstantU

  Dramatic Reversal untaps all (or many) permanents, refreshing Serum Powder's tap activation.
• Blinkmoth Infusion

  12UU

  InstantU

  Blinkmoth Infusion untaps all (or many) permanents, refreshing Serum Powder's tap activation.
• Rimewind Taskmage

  1U

  Creature — Human WizardU

  One-directional refresh: one card can untap permanents the other wants to reuse. Not self-sustaining on its own — the untapper has to keep showing up.
• Teferi, Temporal Pilgrim

  3UU

  Legendary Planeswalker — TeferiU

  Serum Powder draws a large number of cards, enabling Teferi, Temporal Pilgrim's draw-payoff or weaponized-draw effect.
• Ob Nixilis Reignited

  3BB

  Legendary Planeswalker — NixilisB

  Serum Powder draws a large number of cards, enabling Ob Nixilis Reignited's draw-payoff or weaponized-draw effect.
• Emerald Collector

  1U

  Creature — Human PirateGU

  Serum Powder draws a large number of cards, enabling Emerald Collector's draw-payoff or weaponized-draw effect.
• Red Ghost, Intangible Genius

  2UR

  Legendary Creature — Human Scientist VillainRU

  Serum Powder draws a large number of cards, enabling Red Ghost, Intangible Genius's draw-payoff or weaponized-draw effect.
• Stinkweed Imp

  2B

  Creature — ImpB

  Serum Powder draws a large number of cards, enabling Stinkweed Imp's draw-payoff or weaponized-draw effect.
• The Rise of Sozin // Fire Lord Sozin

  4BB

  Enchantment — Saga // Legendary Creature — Human NobleB

  Serum Powder draws a large number of cards, enabling The Rise of Sozin's draw-payoff or weaponized-draw effect.
• Sheoldred, the Apocalypse

  2BB

  Legendary Creature — Phyrexian PraetorB

  Serum Powder draws a large number of cards, enabling Sheoldred, the Apocalypse's draw-payoff or weaponized-draw effect.
• Kid Loki

  U

  Legendary Creature — God Hero VillainU

  Serum Powder draws a large number of cards, enabling Kid Loki's draw-payoff or weaponized-draw effect.
• Kami of the Crescent Moon

  UU

  Legendary Creature — SpiritU

  Serum Powder draws a large number of cards, enabling Kami of the Crescent Moon's draw-payoff or weaponized-draw effect.