Confidence:StrongSolidPlausibleTentativeSpeculative

• Mikey & Leo, Chaos & Order

  G/WG/W

  Legendary Creature — Mutant Ninja TurtleGW

  Both cards trigger when a counter is placed — they fire together.
• Hollowmurk Siege

  BG

  EnchantmentBG

  Both cards trigger when a counter is placed — they fire together.
• Felix Five-Boots

  2BGU

  Legendary Creature — Ooze RogueBGU

  Felix Five-Boots makes Hapatra, Vizier of Poisons's triggered ability trigger an additional time — each time it fires, you get it twice. Value, not a loop.
• Generous Patron

  2G

  Creature — Elf AdvisorG

  Both cards trigger when a counter is placed — they fire together.
• Aphelia, Viper Whisperer

  1B

  Legendary Creature — Gorgon AssassinBG

  Both cards produce the same kind of effect (shared token subtype).
• Delney, Streetwise Lookout

  2W

  Legendary Creature — Human ScoutW

  Delney, Streetwise Lookout makes Hapatra, Vizier of Poisons's triggered ability trigger an additional time — each time it fires, you get it twice. Value, not a loop.
• Annie Joins Up

  1RGW

  Legendary EnchantmentGRW

  Annie Joins Up makes Hapatra, Vizier of Poisons's triggered ability trigger an additional time — each time it fires, you get it twice. Value, not a loop.
• Auntie Ool, Cursewretch

  1BRG

  Legendary Creature — Goblin WarlockBGR

  Both cards trigger when a counter is placed — they fire together.
• Roaming Throne

  4

  Artifact Creature — GolemC

  Roaming Throne makes Hapatra, Vizier of Poisons's triggered ability trigger an additional time — each time it fires, you get it twice. Value, not a loop.
• The Great Goblin

  1B/RB/R

  Legendary Creature — Goblin NobleBR

  Both cards trigger when a counter is placed — they fire together.
• Obelisk Spider

  1BG

  Creature — SpiderBG

  Both cards trigger when a counter is placed — they fire together.
• Kros, Defense Contractor

  1GWU

  Legendary Creature — Cat AdvisorGUW

  Both cards trigger when a counter is placed — they fire together.
• Mirror Room // Fractured Realm

  2U5UU

  Enchantment — Room // Enchantment — RoomU

  Mirror Room makes Hapatra, Vizier of Poisons's triggered ability trigger an additional time — each time it fires, you get it twice. Value, not a loop.
• Wickersmith's Tools

  3

  ArtifactC

  Both cards trigger when a counter is placed — they fire together.
• Sosuke's Summons

  2G

  SorceryG

  Both cards produce the same kind of effect (shared token subtype).
• Nest of Scarabs

  2B

  EnchantmentB

  Both cards trigger when a counter is placed — they fire together.
• Wizard's Staff

  1U

  Artifact — EquipmentU

  Wizard's Staff makes Hapatra, Vizier of Poisons's triggered ability trigger an additional time — each time it fires, you get it twice. Value, not a loop.
• Captain Marvel, Apex Avenger

  5RW

  Legendary Creature — Human Kree HeroRW

  Both cards trigger when a counter is placed — they fire together.
• Stalwart Successor

  1BG

  Creature — Human WarriorBG

  Both cards trigger when a counter is placed — they fire together.
• Flourishing Defenses

  4G

  EnchantmentG

  Both cards trigger when a counter is placed — they fire together.
• Bold Plagiarist

  3B

  Creature — Vampire RogueB

  Both cards trigger when a counter is placed — they fire together.
• All Will Be One

  3RR

  EnchantmentR

  Both cards trigger when a counter is placed — they fire together.
• Archivist of Gondor

  2U

  Creature — Human AdvisorU

  Both cards trigger on damage dealt — they fire together.
• Sygg, Wanderwine Wisdom // Sygg, Wanderbrine Shield

  1U

  Legendary Creature — Merfolk Wizard // Legendary Creature — Merfolk RogueUW

  Both cards trigger on damage dealt — they fire together.
• Reanimate

  B

  SorceryB

  Reanimate puts Hapatra, Vizier of Poisons onto the battlefield from a graveyard without casting it, so its mana cost is never paid.