Pyromancy

{2}{R}{R} · Enchantment

{3}, Discard a card at random: This enchantment deals damage to any target equal to the mana value of the discarded card.

Motor: se resuelve a mano

Rulings (2)

A card with X in the cost is treated as X=0.
Wizards of the Coast · 2004-10-04
You pick the target before you know which card is going to be discarded.
Wizards of the Coast · 2004-10-04