Midnight Banshee is a rare Creature — Spirit card from Shadowmoor (SHM), collector number 72. Current market price: $3.84 (foil $18.27), TCGplayer market prices via Scryfall.
Wither (This deals damage to creatures in the form of -1/-1 counters.) At the beginning of your upkeep, put a -1/-1 counter on each nonblack creature.