Mist of Stagnation is a rare Enchantment card from Judgment (JUD), collector number 48. Current market price: $0.51 (foil $7.85), TCGplayer market prices via Scryfall.
Permanents don't untap during their controllers' untap steps. At the beginning of each player's upkeep, that player chooses a permanent for each card in their graveyard, then untaps those permanents.