Confidence:StrongSolidPlausibleTentativeSpeculative

• Mechanized Production

  2UU

  Enchantment — AuraU

  Alternate win condition: put the wincon on ONE of the tokens the other card produces (tokens of a batch share a name — Servos, Thopters, Treasures), and every further copy counts toward the same-name total.
• Baron Helmut Zemo

  BBB

  Legendary Creature — Human Noble VillainB

  Copy engine: one card makes a copy of a creature every turn, and the other's enter-the-battlefield effect rewards each copy. Real, repeatable value — the partner can't untap or re-enter the copier, so it never goes infinite.
• Stone Idol Trap

  5R

  Instant — TrapR

  Both cards produce the same kind of effect (shared token subtype).
• Tezzeret, Cruel Captain

  3

  Legendary Planeswalker — TezzeretC

  Both cards trigger when a creature enters the battlefield — they fire together.
• Lagrella, the Magpie

  GWU

  Legendary Creature — Human SoldierGUW

  Both cards trigger when a creature enters the battlefield — they fire together.
• April O'Neil, Live on the Scene

  1U

  Legendary Creature — Human DetectiveU

  Both cards trigger when a creature enters the battlefield — they fire together.
• Elvish Archivist

  1G

  Creature — Elf ArtificerG

  Both cards trigger when a creature enters the battlefield — they fire together.
• Brainstealer Dragon

  5BB

  Creature — Dragon HorrorB

  Both cards trigger when a creature enters the battlefield — they fire together.
• Prowl, Stoic Strategist // Prowl, Pursuit Vehicle

  3W

  Legendary Artifact Creature — Robot // Legendary Artifact — VehicleW

  Both cards trigger when a creature enters the battlefield — they fire together.
• Marneus Calgar

  2WUB

  Legendary Creature — Astartes WarriorBUW

  Both cards trigger when a creature enters the battlefield — they fire together.
• Sarinth Steelseeker

  1G

  Creature — Human Artificer ScoutG

  Both cards trigger when a creature enters the battlefield — they fire together.
• Amulet of Vigor

  1

  ArtifactC

  Both cards trigger when a creature enters the battlefield — they fire together.
• The Mighty Thor, Jane Foster

  1WU

  Legendary Creature — Human God HeroUW

  Both cards trigger when a creature enters the battlefield — they fire together.
• Tetzin, Gnome Champion // The Golden-Gear Colossus

  URW

  Legendary Artifact Creature — Gnome // Legendary Artifact Creature — GnomeRUW

  Both cards trigger when a creature enters the battlefield — they fire together.
• Losheel, Clockwork Scholar

  2W

  Legendary Creature — Elephant ArtificerW

  Both cards trigger when a creature enters the battlefield — they fire together.
• Tome of Legends

  2

  Artifact — BookC

  Both cards trigger when a creature enters the battlefield — they fire together.
• Weapons Manufacturing

  1R

  EnchantmentR

  Both cards trigger when a creature enters the battlefield — they fire together.
• Masterwork of Ingenuity

  1

  Artifact — EquipmentC

  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.).
• Mister Fantastic, Reed Richards

  3U

  Legendary Creature — Human Scientist HeroU

  Both cards trigger when a creature enters the battlefield — they fire together.
• Merry, Warden of Isengard

  1GW

  Legendary Creature — Halfling AdvisorGW

  Both cards trigger when a creature enters the battlefield — they fire together.
• Corruption of Towashi

  4U

  EnchantmentU

  Both cards trigger when a creature enters the battlefield — they fire together.
• Cloakwood Swarmkeeper

  G

  Creature — Elf RangerG

  Both cards trigger when a creature enters the battlefield — they fire together.
• Yoshimaru, Ever Faithful

  W

  Legendary Creature — DogW

  Both cards trigger when a creature enters the battlefield — they fire together.
• Threats Around Every Corner

  3G

  EnchantmentG

  Both cards trigger when a creature enters the battlefield — they fire together.
• Golbez, Crystal Collector

  UB

  Legendary Creature — Human WizardBU

  Both cards trigger when a creature enters the battlefield — they fire together.