Chains of Mephistopheles is a rare Enchantment card from Legends (LEG), collector number 91. Current market price: $1,260.44, TCGplayer market prices via Scryfall.
If a player would draw a card except the first one they draw in each of their draw steps, that player discards a card instead. If the player discards a card this way, they draw a card. If the player doesn't discard a card this way, they mill a card.