Confidence:StrongSolidPlausibleTentativeSpeculative

• Saryth, the Viper's Fang

  2GG

  Legendary Creature — Human WarlockG

  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.
• Bumi, Unleashed

  3RG

  Legendary Creature — Human Noble AllyGR

  Bumi, Unleashed untaps all (or many) permanents, refreshing Gate to Tumbledown's tap activation.
• Wilderness Reclamation

  3G

  EnchantmentG

  Wilderness Reclamation untaps all (or many) permanents, refreshing Gate to Tumbledown's tap activation.
• Sword of Feast and Famine

  3

  Artifact — EquipmentC

  Sword of Feast and Famine untaps all (or many) permanents, refreshing Gate to Tumbledown's tap activation.
• Beledros Witherbloom

  5BG

  Legendary Creature — Elder DragonBG

  Beledros Witherbloom untaps all (or many) permanents, refreshing Gate to Tumbledown's tap activation.
• Emrakul, the Exigent Doom

  10

  Legendary Creature — EldraziC

  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.
• Hope Tender

  1G

  Creature — Human 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.
• Nature's Will

  2GG

  EnchantmentG

  Nature's Will untaps all (or many) permanents, refreshing Gate to Tumbledown's tap activation.
• Deserted Temple

  LandC

  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.
• Instrument of the Bards

  G

  Legendary ArtifactG

  Mana loop: net-positive mana cycle between the two cards.
• Reckless Lackey

  R

  Creature — Goblin PirateR

  Mana loop: net-positive mana cycle between the two cards.
• Currency Converter

  1

  ArtifactC

  Mana loop: net-positive mana cycle between the two cards.
• Kamachal, Ship's Mascot

  2R

  Legendary Creature — Dinosaur PirateR

  Mana loop: net-positive mana cycle between the two cards.
• Stark Industries Executive

  R

  Creature — Human AdvisorR

  Mana loop: net-positive mana cycle between the two cards.
• Forsworn Paladin

  B

  Creature — Human KnightB

  Mana loop: net-positive mana cycle between the two cards.
• Ashnod, Flesh Mechanist

  B

  Legendary Creature — Human ArtificerB

  Mana loop: net-positive mana cycle between the two cards.
• Wizard's Rockets

  1

  ArtifactC

  Mana loop: net-positive mana cycle between the two cards.
• A-Geology Enthusiast

  2UU

  Creature — Human ArtificerU

  Mana loop: net-positive mana cycle between the two cards.
• Gleaming Splendor

  1W

  EnchantmentW

  Mana loop: net-positive mana cycle between the two cards.
• Contested Game Ball

  2

  ArtifactC

  Mana loop: net-positive mana cycle between the two cards.
• Discerning Financier

  2W

  Creature — Human NobleW

  Mana loop: net-positive mana cycle between the two cards.
• Redshift, Rocketeer Chief

  RG

  Legendary Creature — Goblin PilotGR

  Mana loop: net-positive mana cycle between the two cards.
• Treasure Dredger

  1B

  Creature — Human RogueB

  Mana loop: net-positive mana cycle between the two cards.
• Fire Lord Ozai

  3B

  Legendary Creature — Human NobleBR

  Mana loop: net-positive mana cycle between the two cards.
• A-Thran Spider

  3

  Artifact Creature — SpiderC

  Mana loop: net-positive mana cycle between the two cards.