Confidence:StrongSolidPlausibleTentativeSpeculative

• Sarkhan's Unsealing

  3R

  EnchantmentR

  Both cards trigger when a spell is cast — they fire together.
• Quintorius Kand

  3RW

  Legendary Planeswalker — QuintoriusRW

  Both cards trigger when a spell is cast — they fire together.
• Copperhorn Scout

  G

  Creature — Elf ScoutG

  Copperhorn Scout untaps all (or many) permanents, refreshing Runadi, Behemoth Caller's tap activation.
• Kasla, the Broken Halo

  3URW

  Legendary Creature — Angel AllyRUW

  Both cards trigger when a spell is cast — they fire together.
• White Plume Adventurer

  2W

  Creature — Orc ClericW

  White Plume Adventurer untaps all (or many) permanents, refreshing Runadi, Behemoth Caller's tap activation.
• 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.
• Sorin of House Markov // Sorin, Ravenous Neonate

  1B

  Legendary Creature — Human Noble // Legendary Planeswalker — SorinBW

  Both cards trigger when a spell is cast — they fire together.
• Harmonic Prodigy

  1R

  Creature — Human WizardR

  Harmonic Prodigy makes Runadi, Behemoth Caller's triggered ability trigger an additional time — each time it fires, you get it twice. Value, not a loop.
• Surtr, Fiery Jötun

  3RR

  Legendary Creature — Giant God WarriorR

  Both cards trigger when a spell is cast — they fire together.
• Drumbellower

  2W

  Creature — SpiritW

  Drumbellower untaps all (or many) permanents, refreshing Runadi, Behemoth Caller'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 Runadi, Behemoth Caller's tap activation.
• Scytheclaw Raptor

  2R

  Creature — DinosaurR

  Both cards trigger when a spell is cast — they fire together.
• Cemetery Gatekeeper

  1R

  Creature — VampireR

  Both cards trigger when a spell is cast — they fire together.
• Tokka & Rahzar, Terrible Twos

  B/RB/R

  Legendary Creature — Turtle Wolf MutantBR

  Both cards trigger when a spell is cast — they fire together.
• Intruder Alarm

  2U

  EnchantmentU

  Intruder Alarm untaps all (or many) permanents, refreshing Runadi, Behemoth Caller's tap activation.
• Earthshaker

  4RR

  Creature — SpiritR

  Both cards trigger when a spell is cast — they fire together.
• Intellectual Offering

  4U

  InstantU

  Intellectual Offering untaps all (or many) permanents, refreshing Runadi, Behemoth Caller's tap activation.
• Roiling Vortex

  1R

  EnchantmentR

  Both cards trigger when a spell is cast — they fire together.
• Dazzling Theater // Prop Room

  3W2W

  Enchantment — Room // Enchantment — RoomW

  Dazzling Theater untaps all (or many) permanents, refreshing Runadi, Behemoth Caller's tap activation.
• Urianger Augurelt

  WU

  Legendary Creature — Elf AdvisorUW

  Both cards trigger when a spell is cast — they fire together.
• Kozilek's Return

  2R

  InstantR

  Both cards trigger when a spell is cast — they fire together.
• Aetherflux Reservoir

  4

  ArtifactC

  Both cards trigger when a spell is cast — they fire together.
• 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.
• Éomer, Marshal of Rohan

  2RR

  Legendary Creature — Human KnightR

  Éomer, Marshal of Rohan untaps all (or many) permanents, refreshing Runadi, Behemoth Caller's tap activation.
• Delney, Streetwise Lookout

  2W

  Legendary Creature — Human ScoutW

  Delney, Streetwise Lookout makes Runadi, Behemoth Caller's triggered ability trigger an additional time — each time it fires, you get it twice. Value, not a loop.