Confidence:StrongSolidPlausibleTentativeSpeculative

• Reanimate

  B

  SorceryB

  Reanimate puts Obsidian Fireheart onto the battlefield from a graveyard without casting it, so its mana cost is never paid.
• Grave Researcher // Reanimate

  2BB

  Creature — Troll Warlock // SorceryB

  Grave Researcher puts Obsidian Fireheart onto the battlefield from a graveyard without casting it, so its mana cost is never paid.
• Sefris of the Hidden Ways

  WUB

  Legendary Creature — Human WizardBUW

  Sefris of the Hidden Ways puts Obsidian Fireheart onto the battlefield from a graveyard without casting it, so its mana cost is never paid.
• Recurring Nightmare

  2B

  EnchantmentB

  Recurring Nightmare puts Obsidian Fireheart onto the battlefield from a graveyard without casting it, so its mana cost is never paid.
• Priest of Fell Rites

  WB

  Creature — Human WarlockBW

  Priest of Fell Rites puts Obsidian Fireheart onto the battlefield from a graveyard without casting it, so its mana cost is never paid.
• Animate Dead

  1B

  Enchantment — AuraB

  Animate Dead puts Obsidian Fireheart onto the battlefield from a graveyard without casting it, so its mana cost is never paid.
• Exhume

  1B

  SorceryB

  Exhume puts Obsidian Fireheart onto the battlefield from a graveyard without casting it, so its mana cost is never paid.
• Life // Death

  G1B

  Sorcery // SorceryBG

  Life puts Obsidian Fireheart onto the battlefield from a graveyard without casting it, so its mana cost is never paid.
• Elrond, Moon-Reader

  2U

  Legendary Creature — Elf NobleU

  Obsidian Fireheart has activated abilities that aren't mana abilities, fueling Elrond, Moon-Reader's activation-trigger.
• Dance of the Dead

  1B

  Enchantment — AuraB

  Dance of the Dead puts Obsidian Fireheart onto the battlefield from a graveyard without casting it, so its mana cost is never paid.
• Victimize

  2B

  SorceryB

  Victimize puts Obsidian Fireheart onto the battlefield from a graveyard without casting it, so its mana cost is never paid.
• Persist

  1B

  SorceryB

  Persist puts Obsidian Fireheart onto the battlefield from a graveyard without casting it, so its mana cost is never paid.
• Soul Exchange

  BB

  SorceryB

  Soul Exchange puts Obsidian Fireheart onto the battlefield from a graveyard without casting it, so its mana cost is never paid.
• Ascent of the Worthy

  1WB

  Enchantment — SagaBW

  Ascent of the Worthy puts Obsidian Fireheart onto the battlefield from a graveyard without casting it, so its mana cost is never paid.
• Necromancy

  2B

  EnchantmentB

  Necromancy puts Obsidian Fireheart onto the battlefield from a graveyard without casting it, so its mana cost is never paid.
• Too Evil to Stay Dead

  2B

  SorceryB

  Too Evil to Stay Dead puts Obsidian Fireheart onto the battlefield from a graveyard without casting it, so its mana cost is never paid.
• Karai, Future of the Foot

  1WB

  Legendary Creature — Human NinjaBW

  Karai, Future of the Foot puts Obsidian Fireheart onto the battlefield from a graveyard without casting it, so its mana cost is never paid.
• One Last Job

  2W

  SorceryW

  One Last Job puts Obsidian Fireheart onto the battlefield from a graveyard without casting it, so its mana cost is never paid.
• Rat King, Verminister

  1B

  Legendary Creature — Rat AvatarB

  Rat King, Verminister puts Obsidian Fireheart onto the battlefield from a graveyard without casting it, so its mana cost is never paid.
• The Falcon, Airship Restored

  2B

  Legendary Artifact — VehicleB

  The Falcon, Airship Restored puts Obsidian Fireheart onto the battlefield from a graveyard without casting it, so its mana cost is never paid.
• Reincarnation

  1GG

  InstantG

  Reincarnation puts Obsidian Fireheart onto the battlefield from a graveyard without casting it, so its mana cost is never paid.
• Liliana's Talent

  BB

  Enchantment — AuraB

  Liliana's Talent puts Obsidian Fireheart onto the battlefield from a graveyard without casting it, so its mana cost is never paid.
• Illusionist's Bracers

  2

  Artifact — EquipmentC

  Obsidian Fireheart has activated abilities that aren't mana abilities, fueling Illusionist's Bracers's activation-trigger.
• Pulsemage Advocate

  2W

  Creature — Human ClericW

  Pulsemage Advocate puts Obsidian Fireheart onto the battlefield from a graveyard without casting it, so its mana cost is never paid.
• Rings of Brighthearth

  3

  ArtifactC

  Obsidian Fireheart has activated abilities that aren't mana abilities, fueling Rings of Brighthearth's activation-trigger.