The Chain Veil is a mythic Legendary Artifact card from The List (PLST), collector number M15-215. Current market price: $19.95, TCGplayer market prices via Scryfall.
At the beginning of your end step, if you didn't activate a loyalty ability of a planeswalker this turn, you lose 2 life. {4}, {T}: For each planeswalker you control, you may activate one of its loyalty abilities once this turn as though none of its loyalty abilities have been activated this turn.