Volcanic Vision

Oracle Text

Return target instant or sorcery card from your graveyard to your hand. Volcanic Vision deals damage equal to that card's converted mana cost to each creature your opponents control. Exile Volcanic Vision.

Card Rulings

2/25/2015 If the target instant or sorcery card becomes an illegal target before Volcanic Vision resolves, the spell won’t resolve and none of its effects will happen. No damage will be dealt and Volcanic Vision won’t be exiled.
2/25/2015 If the target has in its mana cost, X is 0.