Cauldron of Souls is a rare Artifact card from Shadowmoor (SHM), collector number 248. Current market price: $8.83 (foil $43.36), TCGplayer market prices via Scryfall.
{T}: Choose any number of target creatures. Each of those creatures gains persist until end of turn. (When it dies, if it had no -1/-1 counters on it, return it to the battlefield under its owner's control with a -1/-1 counter on it.)