Tasha, the Witch Queen is a mythic Legendary Planeswalker — Tasha card from Battle for Baldur's Gate Promos (PCLB), collector number 294s. Current market price: — (foil $17.97), TCGplayer market prices via Scryfall.
Whenever you cast a spell you don't own, create a 3/3 black Demon creature token. +1: Draw a card. For each opponent, exile up to one target instant or sorcery card from that player's graveyard and put a page counter on it. −3: You may cast a spell from among cards in exile with page counters on them without paying its mana cost. Tasha, the Witch Queen can be your commander.