Damnable Pact [Dragons of Tarkir] ST03-012 where X is that artifact's

where X is that artifact's converted mana cost

“We're going to get you

Set: Modern Horizons 3 Type: Creature — Human Wizard Rarity: Uncommon Cost: {1}{W} Whenever another creature enters the battlefield under your control

Set: Zendikar Rising Prerelease Promos Type: Instant Rarity: Rare Cost: {2}{B}{B} This spell costs {1} less to cast if an opponent controls no basic lands

Set: Secret Lair Drop Series Type: Instant Rarity: Rare Cost: {U/P} ({U/P} can be paid with either {U} or 2 life

Damnable Pact [Dragons of Tarkir] ST03-012 where X is that artifact'sSet: Dragons of Tarkir Type: Sorcery Rarity: Rare Cost: {X}{B}{B} Target player draws X cards and loses X life. "Silumgar's mind is a dark labyrinth, full of grim secrets and subtle traps." Siara, the Dragon's Mouth