Steam Vents [Guilds of Ravnica]Set: Guilds of Ravnica Type: Land Island Mountain Rarity: Rare ({T}: Add {U} or {R}.) As Steam Vents enters the battlefield, you may pay 2 life. If you don't, it enters the battlefield tapped. "A massive new Izzet building project with an unstated purpose? Probably fine." Zija, Simic mutationist

where X is the damage dealt by Arknight Ascendency

Set: Alternate Art Promos Type: Colorless Rarity: Promo Retreat cost: Colorless

" —Liu Bei

Grim Nemesis deals X damage to target creature or planeswalker and you gain X life

and white at the beginning of your next upkeep

" —Seneca

Set: Apocalypse Type: Enchantment Rarity: Rare Cost: {1}{B}{B} At the beginning of your upkeep

Set: EX: Team Rocket Returns Type: Metal

Set: Beta Edition Type: Artifact Rarity: Rare Cost: {3} You may spend white mana as though it were red mana

Set: Miscellaneous Cards Type: Grass Rarity: Promo Retreat cost: Colorless

If both targets are still legal as this ability resolves

Set: Sword & Shield: Black Star Promos Type: Lightning Rarity: Promo Retreat cost: Colorless