Confidence:StrongSolidPlausibleTentativeSpeculative

• Mark of Eviction

  U

  Enchantment — AuraU

  Mark of Eviction bounces a permanent, enabling Breaching Leviathan's recast / spell-cast trigger.
• Asmodeus the Archfiend

  4BB

  Legendary Creature — Devil GodB

  Asmodeus the Archfiend bounces a permanent, enabling Breaching Leviathan's recast / spell-cast trigger.
• Tinybones Joins Up

  B

  Legendary EnchantmentB

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

  4B

  EnchantmentB

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

  1G

  EnchantmentG

  Both cards trigger when a creature enters the battlefield — they fire together.
• Kaito, Dancing Shadow

  2UB

  Legendary Planeswalker — KaitoBU

  Kaito, Dancing Shadow bounces a permanent, enabling Breaching Leviathan's recast / spell-cast trigger.
• Kiora, Behemoth Beckoner

  2G/U

  Legendary Planeswalker — KioraGU

  Both cards trigger when a creature enters the battlefield — they fire together.
• Kiora, Master of the Depths

  2GU

  Legendary Planeswalker — KioraGU

  Both cards trigger when a creature enters the battlefield — they fire together.
• Faramir, Steward of Gondor

  1WU

  Legendary Creature — Human NobleUW

  Both cards trigger when a creature enters the battlefield — they fire together.
• Dour Port-Mage

  1U

  Creature — Frog WizardU

  Dour Port-Mage bounces a permanent, enabling Breaching Leviathan's recast / spell-cast trigger.
• Sidisi's Faithful

  U

  Creature — Snake WizardU

  Sidisi's Faithful bounces a permanent, enabling Breaching Leviathan's recast / spell-cast trigger.
• Teferi, Time Raveler

  1WU

  Legendary Planeswalker — TeferiUW

  Teferi, Time Raveler bounces a permanent, enabling Breaching Leviathan's recast / spell-cast trigger.
• Eye of Singularity

  3W

  World EnchantmentW

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

  G

  Creature — Frog WarriorG

  Mistbreath Elder bounces a permanent, enabling Breaching Leviathan's recast / spell-cast trigger.
• Scalding Viper // Steam Clean

  1R1U

  Creature — Elemental Snake // Sorcery — AdventureRU

  Scalding Viper bounces a permanent, enabling Breaching Leviathan's recast / spell-cast trigger.
• Warden of the Grove

  2G

  Creature — HydraG

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

  U

  SorceryU

  Silent Departure bounces a permanent, enabling Breaching Leviathan's recast / spell-cast trigger.
• Time Wipe

  2WWU

  SorceryUW

  Time Wipe bounces a permanent, enabling Breaching Leviathan's recast / spell-cast trigger.
• Crackleburr

  1U/RU/R

  Creature — ElementalRU

  Crackleburr bounces a permanent, enabling Breaching Leviathan's recast / spell-cast trigger.
• Jace, the Mind Sculptor

  2UU

  Legendary Planeswalker — JaceU

  Jace, the Mind Sculptor bounces a permanent, enabling Breaching Leviathan's recast / spell-cast trigger.
• Jace, Unraveler of Secrets

  3UU

  Legendary Planeswalker — JaceU

  Jace, Unraveler of Secrets bounces a permanent, enabling Breaching Leviathan's recast / spell-cast trigger.
• Grist, Voracious Larva // Grist, the Plague Swarm

  G

  Legendary Creature — Insect // Legendary Planeswalker — GristBG

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

  3GG

  Creature — Elemental TurtleG

  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.
• Trusted Advisor

  U

  Creature — Human AdvisorU

  Trusted Advisor bounces a permanent, enabling Breaching Leviathan's recast / spell-cast trigger.