The Abyss [Legends] Seventh Edition if that creature does not

if that creature does not have the same name as another creature you control or a creature card in your graveyard

Probably fine

Lord of Leaves

Set: Iconic Masters Type: Legendary Creature — Dragon Spirit Rarity: Rare Cost: {4}{B}{B} Flying When Kokusho

Set: Tempest Type: Artifact Rarity: Rare Cost: {1} {3}

The Abyss [Legends] Seventh Edition if that creature does notSet: Legends Type: World Enchantment Rarity: Rare Cost: {3}{B} At the beginning of each player's upkeep, destroy target nonartifact creature that player controls of his or her choice. It can't be regenerated. "An immense river of oblivion is sweeping us away into a nameless abyss." Ernest Renan, Souvenirs d'Enfance et de Jeunesse