Power Sink [Introductory Two-Player Set] Kavu At the beginning of the

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

a profit from an atrocity

"In the drowsy dark cave of the mind

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

The same is true for creature spells you control and creature cards you own that aren't on the battlefield

Power Sink [Introductory Two-Player Set] Kavu At the beginning of theSet: Introductory Two Player Set Type: Instant Rarity: Common Cost: {X}{U} Counter target spell unless its controller pays {X}. If that player doesn't, they tap all lands with mana abilities they control and lose all unspent mana.