Confidence:StrongSolidPlausibleTentativeSpeculative

• 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.
• 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.
• 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.
• Sarinth Steelseeker

  1G

  Creature — Human Artificer ScoutG

  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.
• Tome of Legends

  2

  Artifact — BookC

  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.).
• Merry, Warden of Isengard

  1GW

  Legendary Creature — Halfling AdvisorGW

  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.
• Isu the Abominable

  3UU

  Legendary Snow Creature — YetiGUW

  Both cards trigger when a creature enters the battlefield — they fire together.
• Moon Girl and Devil Dinosaur

  1GU

  Legendary Creature — Human Dinosaur HeroGU

  Both cards trigger when a creature enters the battlefield — they fire together.
• Fire Lord Zuko

  RWB

  Legendary Creature — Human Noble AllyBRW

  Both cards trigger when a creature enters the battlefield — they fire together.
• Baron Bertram Graywater

  2WB

  Legendary Creature — Vampire NobleBW

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

  2

  Artifact Creature — Robot NinjaC

  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.
• Chishiro, the Shattered Blade

  2RG

  Legendary Creature — Snake SamuraiGR

  Both cards trigger when a creature enters the battlefield — they fire together.
• Haliya, Guided by Light

  2W

  Legendary Creature — Human SoldierW

  Both cards trigger when a creature enters the battlefield — they fire together.
• Maralen, Fae Ascendant

  2BGU

  Legendary Creature — Elf Faerie NobleBGU

  Both cards trigger when a creature enters the battlefield — they fire together.
• Tidus, Blitzball Star

  1WU

  Legendary Creature — Human WarriorUW

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

  UB

  Creature — Aetherborn RogueBU

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