Sentient Spell

Flash
When Sentient Spell enters the battlefield,
counter target spell. Sentient Spell gains
X +1/+1 counters, where X is the converted
mana cost of the target spell.
You shouldn't play around with magic. Who knows, it
might not want to play! - Garriba of school Turnen,
two days before being allegedly punched by an uncooperative fireball