The Unknown Wizard is a mythic Legendary Creature — Human Wizard card from Unknown Event (UNK), collector number MZ01. Current market price: $13.62, TCGplayer market prices via Scryfall.
Eminence — As long as The Unknown Wizard is in the command zone or on the battlefield, other playtest cards you cast cost {1} less to cast. Whenever The Unknown Wizard enters or attacks, look at the top ten cards of your library. You may put a legendary playtest card from among them onto the battlefield. Put the rest on the bottom in a random order.