Lunar Convocation is a rare Enchantment card from Bloomburrow (BLB), collector number 366. Current market price: $1.56 (foil $1.80), TCGplayer market prices via Scryfall.
At the beginning of your end step, if you gained life this turn, each opponent loses 1 life. At the beginning of your end step, if you gained and lost life this turn, create a 1/1 black Bat creature token with flying. {1}{B}, Pay 2 life: Draw a card.