Rite of Belzenlok is a rare Enchantment — Saga card from Dominaria Promos (PDOM), collector number 102s. Current market price: — (foil $1.33), TCGplayer market prices via Scryfall.
(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.) I, II — Create two 0/1 black Cleric creature tokens. III — Create a 6/6 black Demon creature token with flying, trample, and "At the beginning of your upkeep, sacrifice another creature. If you can't, this token deals 6 damage to you."