Sphinx's Tutelage is a uncommon Enchantment card from The List (PLST), collector number ORI-76. Current market price: $2.00, TCGplayer market prices via Scryfall.
Whenever you draw a card, target opponent mills two cards. If two nonland cards that share a color were milled this way, repeat this process. {5}{U}: Draw a card, then discard a card.