Confidence:StrongSolidPlausibleTentativeSpeculative

• Kiki-Jiki, Mirror Breaker✓

  2RRR

  Legendary Creature — Goblin ShamanR

  Copy chain: one card creates hasty copies of a creature whose ability or ETB the partner exploits — the canonical Kiki-Jiki / Splinter Twin pattern.
• Lonis, Cryptozoologist

  GU

  Legendary Creature — Snake Elf ScoutGU

  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 Soul Stone

  1B

  Legendary Artifact — Infinity StoneB

  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.
• Lady Sun

  1UU

  Legendary Creature — Human AdvisorU

  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.
• Niambi, Esteemed Speaker

  WU

  Legendary Creature — Human ClericUW

  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 Mind Stone

  1W

  Legendary Artifact — Infinity StoneW

  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.
• Nephalia Smuggler

  U

  Creature — Human RogueU

  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.
• Xu-Ifit, Osteoharmonist

  1BB

  Legendary Creature — Human WizardB

  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.
• Tawnos's Coffin

  4

  ArtifactC

  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.
• Qarsi High Priest

  B

  Creature — Human ClericB

  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.
• Coastal Wizard

  2UU

  Creature — Human WizardU

  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.
• Clement, the Worrywort

  1GU

  Legendary Creature — Frog DruidGU

  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.
• Dino DNA

  1

  ArtifactC

  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 Master, Transcendent

  1BGU

  Legendary Artifact Creature — MutantBGU

  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.
• Shieldmage Advocate

  2W

  Creature — Human ClericW

  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.
• Angel of Condemnation

  2WW

  Creature — AngelW

  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.
• Tawnos, Solemn Survivor

  1U

  Legendary Creature — Human ArtificerBUW

  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.
• Cursed Mirror

  2R

  ArtifactR

  One-shot copy enabler: a card enters as a copy of another (Phantasmal Image, Body Double, Phyrexian Metamorph), firing the partner's substantive ETB once. Not a repeating chain — fires once on entry — but valuable when the partner's ETB is combo-grade (graveyard reanimator, mana doubler, etc.).
• Jill, Shiva's Dominant // Shiva, Warden of Ice

  2U

  Legendary Creature — Human Noble Warrior // Legendary Enchantment Creature — Saga ElementalU

  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.
• Tradewind Rider

  3U

  Creature — SpiritU

  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 Beamtown Bullies

  1BRG

  Legendary Creature — Ogre Devil WarriorBGR

  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.
• Aether Vial

  1

  ArtifactC

  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.
• Satsuki, the Living Lore

  GW

  Legendary Creature — Human DruidGW

  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.
• Distinguished Conjurer

  1W

  Creature — Human WizardW

  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.
• Arcane Artisan

  2U

  Creature — Human WizardU

  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.

• WithTempestra, Dame of Games1RR

  Copy chain: each card copies the other (or both copy a third), generating arbitrary copies. These two can't keep the loop going alone — add one of these to complete it:

  Magda, Brazen Outlaw1RRose Room Treasurer3RSharp-Eyed Rookie1GKingpin, Wilson Fisk3BGemcutter Buccaneer3RGanax, Astral Hunter4R
  Show cards