Revelsong Horn [Shadowmoor] Kaladesh where X is the number

where X is the number of creatures on the battlefield

Set: Dragons of Tarkir Type: Instant Rarity: Rare Cost: {X}{R}{R} Exile the top X cards of your library

Everybody dies

Destroy target creature with power X or less

Set: Invasion Type: Creature — Metathran Wizard Rarity: Uncommon Cost: {1}{U} {2}: Target white or black creature gains flying until end of turn

Revelsong Horn [Shadowmoor] Kaladesh where X is the numberSet: Shadowmoor Type: Artifact Rarity: Uncommon Cost: {2} {1}, {T}, Tap an untapped creature you control: Target creature gets +1 +1 until end of turn. A deflated sigh breathed into the horn emerges as an inspiring melody.