Confidence:StrongSolidPlausibleTentativeSpeculative

• Grimgrin, Corpse-Born

  3UB

  Legendary Creature — Zombie WarriorBU

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

  1W

  Creature — Human SoldierW

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

  2W

  ArtifactW

  Token-fuel engine: one side keeps producing untapped tokens that pay the other's tap costs, and the output feeds the loop again — Squirrel Nest with Earthcraft is the classic shape.
• The Legend of Kuruk // Avatar Kuruk

  2UU

  Enchantment — Saga // Legendary Creature — AvatarU

  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.
• Belisarius Cawl

  2WU

  Legendary Artifact Creature — HumanUW

  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.
• Skirsdag High Priest

  1B

  Creature — Human ClericB

  Token-fuel engine: one side keeps producing untapped tokens that pay the other's tap costs, and the output feeds the loop again — Squirrel Nest with Earthcraft is the classic shape.
• Prosperous Partnership

  1RW

  EnchantmentRW

  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.
• Sky Hussar

  3WU

  Creature — Human KnightUW

  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.
• Chained Brute

  1R

  Creature — DevilR

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

  GW

  Creature — Elf ShamanGW

  Token-fuel engine: one side keeps producing untapped tokens that pay the other's tap costs, and the output feeds the loop again — Squirrel Nest with Earthcraft is the classic shape.
• Aura of Dominion

  UU

  Enchantment — AuraU

  Token-fuel engine: one side keeps producing untapped tokens that pay the other's tap costs, and the output feeds the loop again — Squirrel Nest with Earthcraft is the classic shape.
• Midnight Guard

  2W

  Creature — Human SoldierW

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

  3BB

  Creature — HorseB

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

  5UU

  Creature — SerpentU

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

  7

  Artifact Creature — GolemC

  Token-fuel engine: one side keeps producing untapped tokens that pay the other's tap costs, and the output feeds the loop again — Squirrel Nest with Earthcraft is the classic shape.
• Kithkeeper

  6W

  Creature — ElementalW

  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.
• Lita, Mechanical Engineer

  2W

  Legendary Artifact Creature — ArtificerW

  Lita, Mechanical Engineer untaps all (or many) permanents, refreshing Reservoir Kraken's tap activation.
• Copperhorn Scout

  G

  Creature — Elf ScoutG

  Copperhorn Scout untaps all (or many) permanents, refreshing Reservoir Kraken's tap activation.
• Crackleburr

  1U/RU/R

  Creature — ElementalRU

  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.
• Elspeth, Storm Slayer

  3WW

  Legendary Planeswalker — ElspethW

  One card multiplies the tokens the other creates — a token doubler pointed at a steady token source.
• White Plume Adventurer

  2W

  Creature — Orc ClericW

  White Plume Adventurer untaps all (or many) permanents, refreshing Reservoir Kraken's tap activation.
• Jace, Ingenious Mind-Mage

  4UU

  Legendary Planeswalker — JaceU

  Jace, Ingenious Mind-Mage untaps all (or many) permanents, refreshing Reservoir Kraken's tap activation.
• Murkfiend Liege

  2G/UG/UG/U

  Creature — HorrorGU

  Murkfiend Liege untaps all (or many) permanents, refreshing Reservoir Kraken's tap activation.
• Aggravated Assault

  2R

  EnchantmentR

  Aggravated Assault untaps all (or many) permanents, refreshing Reservoir Kraken's tap activation.
• The Thirteenth Doctor

  1GU

  Legendary Creature — Time Lord DoctorGU

  The Thirteenth Doctor untaps all (or many) permanents, refreshing Reservoir Kraken's tap activation.