Dark Confidant
Creature — Human Wizard
At the beginning of your upkeep, reveal the top card of your library and put that card into your hand. You lose life equal to its mana value.
Greatness, at any cost.
Mark Zug
Double Masters (2XM)
• #342Rulings
If a card in a player's library has {X} in its mana cost, X is considered to be 0.
(wotc • 2020-08-07)
Rulings
If a card in a player's library has {X} in its mana cost, X is considered to be 0.
(wotc • 2020-08-07)