Debaucherous Duke

Whenever Debaucherous Duke becomes the
target of a spell, you may pay life equal to
that spell's converted mana cost. If you do,
counter that spell. If it would go to a
graveyard this turn, exile it underneath Debaucherous Duke instead.
Pay 4 life: You may cast any spell that is exiled
underneath Debaucherous Duke without
paying its mana cost. Activate this ability
only any time you could cast a sorcery.