Ursula's Pact

Cast a spell from your hand without paying its
mana cost: At the beginning of your next
upkeep, you may pay twice the mana cost of that
spell or you can't cast spells that share a card
type with that card for the remainder of the
game. Any opponent may activate this ability.
Whenever an opponent fails to pay twice the
mana cost for a spell they cast using this ability,
you draw cards equal to that spell's converted
mana cost.