Bellow of Subjugation

Impose (Life lost by your opponents can help cast this
spell. Each 1 life lost by an opponent this turn pays for {1}.)
Search your library for an instant or sorcery card
with converted mana cost X or less. You may cast
that card without paying its mana cost. Then
shuffle your library. If a card cast this way would
be put into your graveyard this turn, exile it
instead.