Darkblast is a uncommon Instant card from GRN Guild Kit (GK1), collector number 51. Current market price: $0.49, TCGplayer market prices via Scryfall.
Target creature gets -1/-1 until end of turn. Dredge 3 (If you would draw a card, you may mill three cards instead. If you do, return this card from your graveyard to your hand.)