Confidence:StrongSolidPlausibleTentativeSpeculative

• Quintorius Kand

  3RW

  Legendary Planeswalker — QuintoriusRW

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

  4BB

  Legendary Planeswalker — LilianaB

  Both cards trigger when a spell is cast — they fire together.
• Fin Fang Foom

  2RR

  Legendary Creature — Alien Dragon VillainR

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

  5B

  Creature — Troll WarlockB

  Both cards trigger when a spell is cast — they fire together.
• A-Wizard Class

  U

  Enchantment — ClassU

  Draw pair: both cards engage with card draw. With a damage-or-draw trigger between them they form a draw engine.
• Ashling, Flame Dancer

  2RR

  Legendary Creature — Elemental ShamanR

  Both cards trigger when a spell is cast — they fire together.
• Smoldering Egg // Ashmouth Dragon

  1R

  Creature — Dragon Egg // Creature — DragonR

  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.
• Scytheclaw Raptor

  2R

  Creature — DinosaurR

  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.
• Roiling Vortex

  1R

  EnchantmentR

  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.
• Cemetery Gatekeeper

  1R

  Creature — VampireR

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

  UR

  SorceryRU

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

  WWBB

  Creature — Kor WarlockBW

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

  2R

  Creature — Minotaur PilotR

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

  2U

  EnchantmentU

  Unstoppable Plan untaps all (or many) permanents, refreshing A-Spell Satchel's tap activation.
• Firja, Judge of Valor

  2WBB

  Legendary Creature — Angel ClericBW

  Both cards trigger when a spell is cast — they fire together.
• Invasion of Karsus // Refraction Elemental

  2RR

  Battle — Siege // Creature — ElementalR

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

  2R

  Creature — Lizard WarlockR

  Both cards trigger when a spell is cast — they fire together.
• Captain Ripley Vance

  2R

  Legendary Creature — Human PirateR

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

  1R

  InstantR

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

  4

  ArtifactC

  Unwinding Clock untaps all (or many) permanents, refreshing A-Spell Satchel's tap activation.
• Innkeeper's Talent

  1G

  Enchantment — ClassG

  Counter synergy: both cards work with the same kind of counters, so their effects stack in a counters deck. Not necessarily a closed loop on its own.
• Labyrinth Champion

  3R

  Creature — Human WarriorR

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