Teferi's Curse is a common Enchantment — Aura card from Mirage (MIR), collector number 96. Current market price: $0.15, TCGplayer market prices via Scryfall.
Enchant artifact or creature Enchanted permanent has phasing. (It phases in or out before its controller untaps during each of their untap steps. While it's phased out, it's treated as though it doesn't exist.)