Lady Safiria, Frigid Sorceress

{w}{w}{u} Put a Chill counter on target creature.
{w}{u} Target opponent must pay X mana to
attack with creatures that have chill counters
on them where X is the number of chill counters
on each individual creature attacking.
{1}{w}{u}{b} Exile target creature with 3 or more
chill counters on it.
"They said you were a cold hearted witch!"
"Who said they were wrong?"