Confidence:StrongSolidPlausibleTentativeSpeculative

• Intruder Alarm

  2U

  EnchantmentU

  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.
• Aura of Dominion

  UU

  Enchantment — AuraU

  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.
• Tolarian Kraken

  4UU

  Creature — KrakenU

  Untap loop: each side can untap what the other taps — a genuine mutual refresh engine.
• Basri, Tomorrow's Champion

  W

  Legendary Creature — Human KnightW

  Basri, Tomorrow's Champion has cycling, and Leonardo da Vinci pays off whenever a card is cycled — the Astral Slide / Lightning Rift engine shape.
• Pia Nalaar, Consul of Revival

  RW

  Legendary Creature — Human ArtificerRW

  Both cards produce the same kind of effect (shared token subtype).
• Unearth

  B

  SorceryB

  Unearth has cycling, and Leonardo da Vinci pays off whenever a card is cycled — the Astral Slide / Lightning Rift engine shape.
• Flame Blitz

  R

  EnchantmentR

  Flame Blitz has cycling, and Leonardo da Vinci pays off whenever a card is cycled — the Astral Slide / Lightning Rift engine shape.
• Copperhorn Scout

  G

  Creature — Elf ScoutG

  Copperhorn Scout untaps all (or many) permanents, refreshing Leonardo da Vinci's tap activation.
• Jolted Awake

  W

  SorceryW

  Jolted Awake has cycling, and Leonardo da Vinci pays off whenever a card is cycled — the Astral Slide / Lightning Rift engine shape.
• Decree of Annihilation

  8RR

  SorceryR

  Decree of Annihilation has cycling, and Leonardo da Vinci pays off whenever a card is cycled — the Astral Slide / Lightning Rift engine shape.
• Vedalken Aethermage

  1U

  Creature — Vedalken WizardU

  Vedalken Aethermage has cycling, and Leonardo da Vinci 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 Leonardo da Vinci's tap activation.
• Jace, Ingenious Mind-Mage

  4UU

  Legendary Planeswalker — JaceU

  Jace, Ingenious Mind-Mage untaps all (or many) permanents, refreshing Leonardo da Vinci's tap activation.
• Aggravated Assault

  2R

  EnchantmentR

  Aggravated Assault untaps all (or many) permanents, refreshing Leonardo da Vinci's tap activation.
• Decree of Pain

  6BB

  SorceryB

  Decree of Pain has cycling, and Leonardo da Vinci pays off whenever a card is cycled — the Astral Slide / Lightning Rift engine shape.
• Elvish Aberration

  5G

  Creature — Elf MutantG

  Elvish Aberration has cycling, and Leonardo da Vinci pays off whenever a card is cycled — the Astral Slide / Lightning Rift engine shape.
• The Thirteenth Doctor

  1GU

  Legendary Creature — Time Lord DoctorGU

  The Thirteenth Doctor untaps all (or many) permanents, refreshing Leonardo da Vinci's tap activation.
• Veteran Beastrider

  1GW

  Creature — Human KnightGW

  Veteran Beastrider untaps all (or many) permanents, refreshing Leonardo da Vinci's tap activation.
• Neutralize

  1UU

  InstantU

  Neutralize has cycling, and Leonardo da Vinci pays off whenever a card is cycled — the Astral Slide / Lightning Rift engine shape.
• Resounding Thunder

  2R

  InstantBGR

  Resounding Thunder has cycling, and Leonardo da Vinci pays off whenever a card is cycled — the Astral Slide / Lightning Rift engine shape.
• Boon of the Wish-Giver

  4UU

  SorceryU

  Boon of the Wish-Giver has cycling, and Leonardo da Vinci pays off whenever a card is cycled — the Astral Slide / Lightning Rift engine shape.
• Thopter Assembly

  6

  Artifact Creature — ThopterC

  Both cards produce the same kind of effect (shared token subtype).
• Spectacular Pileup

  3WW

  SorceryW

  Spectacular Pileup has cycling, and Leonardo da Vinci pays off whenever a card is cycled — the Astral Slide / Lightning Rift engine shape.
• Webstrike Elite

  GG

  Creature — Insect ArcherG

  Webstrike Elite has cycling, and Leonardo da Vinci pays off whenever a card is cycled — the Astral Slide / Lightning Rift engine shape.