Avatar of Woe is a rare Creature — Avatar card from Prophecy (PCY), collector number 56. Current market price: $15.50 (foil $227.79), TCGplayer market prices via Scryfall.
If there are ten or more creature cards total in all graveyards, this spell costs {6} less to cast. Fear (This creature can't be blocked except by artifact creatures and/or black creatures.) {T}: Destroy target creature. It can't be regenerated.