Alhammarret, High Arbiter is a rare Legendary Creature — Sphinx card from Magic Origins Promos (PORI), collector number 43s. Current market price: — (foil $0.94), TCGplayer market prices via Scryfall.
Flying As Alhammarret enters, each opponent reveals their hand. You choose the name of a nonland card revealed this way. Your opponents can't cast spells with the chosen name (as long as this creature is on the battlefield).