Confidence:StrongSolidPlausibleTentativeSpeculative

• Crackleburr

  1U/RU/R

  Creature — ElementalRU

  Untap loop: each side can untap what the other taps — a genuine mutual refresh engine.
• Karn, Living Legacy

  4

  Legendary Planeswalker — KarnC

  Untap loop: each side can untap what the other taps — a genuine mutual refresh engine.
• Krovikan Plague

  2B

  Enchantment — AuraB

  Untap loop: each side can untap what the other taps — a genuine mutual refresh engine.
• Hand of Justice

  5W

  Creature — AvatarW

  Untap loop: each side can untap what the other taps — a genuine mutual refresh engine.
• Ghirapur Aether Grid

  2R

  EnchantmentR

  Untap loop: each side can untap what the other taps — a genuine mutual refresh engine.
• Explosive Singularity

  8RR

  SorceryR

  Untap loop: each side can untap what the other taps — a genuine mutual refresh engine.
• Burn at the Stake

  2RRR

  SorceryR

  Untap loop: each side can untap what the other taps — a genuine mutual refresh engine.
• Unerring Sling

  3

  ArtifactC

  Untap loop: each side can untap what the other taps — a genuine mutual refresh engine.
• Keldon Battlewagon

  5

  Artifact Creature — JuggernautC

  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.
• Susur Secundi, Void Altar

  Land — PlanetB

  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.
• Chandra, Torch of Defiance

  2RR

  Legendary Planeswalker — ChandraR

  Chandra, Torch of Defiance produces damage that can kill creatures, enabling Galvanic Juggernaut's death-trigger or removal payoff.
• Scavenger Regent // Exude Toxin

  3BXBB

  Creature — Dragon // Sorcery — OmenB

  Scavenger Regent produces damage that can kill creatures, enabling Galvanic Juggernaut's death-trigger or removal payoff.
• Chevill, Bane of Monsters

  BG

  Legendary Creature — Human RogueBG

  Both cards trigger when a creature dies — they fire together.
• Minsc & Boo, Timeless Heroes

  2RG

  Legendary Planeswalker — MinscGR

  Minsc & Boo, Timeless Heroes produces damage that can kill creatures, enabling Galvanic Juggernaut's death-trigger or removal payoff.
• Elesh Norn, Grand Cenobite

  5WW

  Legendary Creature — Phyrexian PraetorW

  Elesh Norn, Grand Cenobite produces damage that can kill creatures, enabling Galvanic Juggernaut's death-trigger or removal payoff.
• Nicol Bolas, the Ravager // Nicol Bolas, the Arisen

  1UBR

  Legendary Creature — Elder Dragon // Legendary Planeswalker — BolasBRU

  Nicol Bolas, the Ravager produces damage that can kill creatures, enabling Galvanic Juggernaut's death-trigger or removal payoff.
• Phlage, Titan of Fire's Fury

  1RW

  Legendary Creature — Elder GiantRW

  Phlage, Titan of Fire's Fury produces damage that can kill creatures, enabling Galvanic Juggernaut's death-trigger or removal payoff.
• Sarkhan's Unsealing

  3R

  EnchantmentR

  Sarkhan's Unsealing produces damage that can kill creatures, enabling Galvanic Juggernaut's death-trigger or removal payoff.
• Wrenn and Six

  RG

  Legendary Planeswalker — WrennGR

  Wrenn and Six produces damage that can kill creatures, enabling Galvanic Juggernaut's death-trigger or removal payoff.
• Chandra, Flameshaper

  5RR

  Legendary Planeswalker — ChandraR

  Chandra, Flameshaper produces damage that can kill creatures, enabling Galvanic Juggernaut's death-trigger or removal payoff.
• Chandra's Defeat

  R

  InstantR

  Chandra's Defeat produces damage that can kill creatures, enabling Galvanic Juggernaut's death-trigger or removal payoff.
• Lavabrink Floodgates

  3R

  ArtifactR

  Lavabrink Floodgates produces damage that can kill creatures, enabling Galvanic Juggernaut's death-trigger or removal payoff.
• Form of the Dragon

  4RRR

  EnchantmentR

  Form of the Dragon produces damage that can kill creatures, enabling Galvanic Juggernaut's death-trigger or removal payoff.
• Chandra, Hope's Beacon

  4RR

  Legendary Planeswalker — ChandraR

  Chandra, Hope's Beacon produces damage that can kill creatures, enabling Galvanic Juggernaut's death-trigger or removal payoff.
• Hammerfist Giant

  4RR

  Creature — Giant WarriorR

  Hammerfist Giant produces damage that can kill creatures, enabling Galvanic Juggernaut's death-trigger or removal payoff.