Mana Echoes [Onslaught]

Mana Echoes [Onslaught]Set: Onslaught Type: Enchantment Rarity: Rare Cost: {2}{R}{R} Whenever a creature enters the battlefield, you may add an amount of {C} equal to the number of creatures you control that share a creature type with it. When the ground is saturated with mana, even the lightest footstep can bring it to the surface.

you may pay {B}

Set: Best of Promos Type: Grass Rarity: Promo Retreat cost: Colorless

destroy all untapped creatures that didn't attack this turn

Set: Black & White: Plasma Freeze Type: Grass Rarity: Promo Retreat cost: Colorless

Set: EX: Legend Maker Type: Fire Rarity: Ultra Rare Retreat cost: Colorless

Set: Avacyn Restored Type: Creature — Angel Rarity: Rare Cost: {1}{W}{W}{W} Flying

Set: Black & White: Plasma Freeze Type: Dragon Rarity: Ultra Rare Retreat cost: Colorless

" —Crovax

Set: EX: Team Magma vs Team Aqua Type: Psychic Rarity: Common Retreat cost: Colorless

Set: XY: Black Star Promos Type: Fighting Rarity: Promo Retreat cost: Colorless

At the beginning of the upkeep of enchanted enchantment's controller

it deals 1 damage to you