Bloodletter of Aclazotz is a mythic Creature — Vampire Demon card from The Lost Caverns of Ixalan Promos (PLCI), collector number 92p. Current market price: $34.53 (foil $38.14), TCGplayer market prices via Scryfall.
Flying If an opponent would lose life during your turn, they lose twice that much life instead. (Damage causes loss of life.)