Great Unclean One is a rare Creature — Demon card from Warhammer 40,000 Commander (40K), collector number 35. Current market price: $4.38, TCGplayer market prices via Scryfall.
Reverberating Summons — At the beginning of your end step, each opponent loses 2 life. Then for each opponent who has less life than you, create a 1/3 black Demon creature token named Plaguebearer of Nurgle.