Herald of Hadar is a common Creature — Human Warlock card from Adventures in the Forgotten Realms (AFR), collector number 108. Current market price: $0.26 (foil $0.25), TCGplayer market prices via Scryfall.
Circle of Death — {5}{B}: Roll a d20. 1—9 | Each opponent loses 2 life. 10—19 | Each opponent loses 2 life and you gain 2 life. 20 | Each opponent loses 2 life and you gain 2 life. Create two Treasure tokens. (They're artifacts with "{T}, Sacrifice this token: Add one mana of any color.")