Imminent Doom [Hour of Devastation Prerelease Promos] Sponge I'm merely setting it free

I'm merely setting it free

Set: Mystery Booster Type: Sorcery Rarity: Common Cost: {R} Draw two cards

Set: Modern Horizons Type: Creature — Plant Wall Rarity: Uncommon Cost: {1}{G} Defender

Set: Modern Masters 2015 Type: Creature — Elemental Rarity: Uncommon Cost: {4}{U} Flying

the player puts it into their graveyard

Imminent Doom [Hour of Devastation Prerelease Promos] Sponge I'm merely setting it freeSet: Hour of Devastation Prerelease Promos Type: Enchantment Rarity: Rare Cost: {2}{R} Imminent Doom enters the battlefield with a doom counter on it. Whenever you cast a spell with mana value equal to the number of doom counters on Imminent Doom, Imminent Doom deals that much damage to any target. Then put a doom counter on Imminent Doom.