The Ancient One (Promo Pack) [The Lost Caverns of Ixalan Promos] Doctor Who −3: Target opponent discards a

−3: Target opponent discards a card

but it doesn't change the base game's core mechanics

Their name

you may cast that card and you may spend mana as though it were mana of any color to cast that spell

The Ancient One (Promo Pack) [The Lost Caverns of Ixalan Promos] Doctor Who −3: Target opponent discards aSet: The Lost Caverns of Ixalan Promos Type: Legendary Creature Spirit God Rarity: Mythic Cost: {U}{B} Descend 8 The Ancient One can't attack or block unless there are eight or more permanent cards in your graveyard. 2UB: Draw a card, then discard a card. When you discard a card this way, target player mills cards equal to its mana value.