Confidence:StrongSolidPlausibleTentativeSpeculative

• Umbral Mantle✓

  3

  Artifact — EquipmentC

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

  G

  Creature — Elf ScoutG

  Copperhorn Scout untaps all (or many) permanents, refreshing Elvish Aberration's tap activation.
• Currency Converter

  1

  ArtifactC

  Elvish Aberration has cycling, and Currency Converter pays off whenever a card is cycled — the Astral Slide / Lightning Rift engine shape.
• White Plume Adventurer

  2W

  Creature — Orc ClericW

  White Plume Adventurer untaps all (or many) permanents, refreshing Elvish Aberration's tap activation.
• Necropotence

  BBB

  EnchantmentB

  Elvish Aberration has cycling, and Necropotence pays off whenever a card is cycled — the Astral Slide / Lightning Rift engine shape.
• Midnight Oil

  2BB

  EnchantmentB

  Elvish Aberration has cycling, and Midnight Oil pays off whenever a card is cycled — the Astral Slide / Lightning Rift engine shape.
• Insidious Roots

  BG

  EnchantmentBG

  Elvish Aberration has cycling, and Insidious Roots pays off whenever a card is cycled — the Astral Slide / Lightning Rift engine shape.
• Veteran Beastrider

  1GW

  Creature — Human KnightGW

  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 Thirteenth Doctor

  1GU

  Legendary Creature — Time Lord DoctorGU

  The Thirteenth Doctor untaps all (or many) permanents, refreshing Elvish Aberration's tap activation.
• Lazotep Chancellor

  UB

  Creature — Zombie WizardBU

  Elvish Aberration has cycling, and Lazotep Chancellor pays off whenever a card is cycled — the Astral Slide / Lightning Rift engine shape.
• Vash, Freelance Archaeologist

  1BG

  Legendary Creature — Human Rogue ScientistBG

  Elvish Aberration has cycling, and Vash, Freelance Archaeologist pays off whenever a card is cycled — the Astral Slide / Lightning Rift engine shape.
• Drumbellower

  2W

  Creature — SpiritW

  Drumbellower untaps all (or many) permanents, refreshing Elvish Aberration's tap activation.
• Plargg, Dean of Chaos // Augusta, Dean of Order

  1R2W

  Legendary Creature — Orc Shaman // Legendary Creature — Human ClericRW

  Plargg, Dean of Chaos untaps all (or many) permanents, refreshing Elvish Aberration's tap activation.
• Intruder Alarm

  2U

  EnchantmentU

  Intruder Alarm untaps all (or many) permanents, refreshing Elvish Aberration's tap activation.
• Intellectual Offering

  4U

  InstantU

  Intellectual Offering untaps all (or many) permanents, refreshing Elvish Aberration's tap activation.
• Dazzling Theater // Prop Room

  3W2W

  Enchantment — Room // Enchantment — RoomW

  Dazzling Theater untaps all (or many) permanents, refreshing Elvish Aberration's tap activation.
• Formidable Speaker

  2G

  Creature — Elf 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.
• Green Goblin, Back for More

  3BB

  Legendary Creature — Goblin Human VillainB

  Elvish Aberration has cycling, and Green Goblin, Back for More pays off whenever a card is cycled — the Astral Slide / Lightning Rift engine shape.
• Éomer, Marshal of Rohan

  2RR

  Legendary Creature — Human KnightR

  Éomer, Marshal of Rohan untaps all (or many) permanents, refreshing Elvish Aberration's tap activation.
• Ivora, Insatiable Heir

  1R

  Legendary Creature — Vampire WarriorR

  Elvish Aberration has cycling, and Ivora, Insatiable Heir pays off whenever a card is cycled — the Astral Slide / Lightning Rift engine shape.
• Ragged Recluse // Odious Witch

  1B

  Creature — Human Peasant // Creature — Human WarlockB

  Elvish Aberration has cycling, and Ragged Recluse pays off whenever a card is cycled — the Astral Slide / Lightning Rift engine shape.
• 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.
• Gideon, Martial Paragon

  4W

  Legendary Planeswalker — GideonW

  Gideon, Martial Paragon untaps all (or many) permanents, refreshing Elvish Aberration's tap activation.
• Prophet of Kruphix

  3GU

  Creature — Human WizardGU

  Prophet of Kruphix untaps all (or many) permanents, refreshing Elvish Aberration's tap activation.
• Unstoppable Plan

  2U

  EnchantmentU

  Unstoppable Plan untaps all (or many) permanents, refreshing Elvish Aberration's tap activation.