Gatekeeper of Malakir is a uncommon Creature — Vampire Warrior card from Duel Decks: Sorin vs. Tibalt (DDK), collector number 8. Current market price: $0.25, TCGplayer market prices via Scryfall.
Kicker {B} (You may pay an additional {B} as you cast this spell.) When this creature enters, if it was kicked, target player sacrifices a creature of their choice.