Mana Vortex

At the beginning of your upkeep, you may put a
magic counter on Mana Vortex. Then you may
reveal cards from the top of your library until
you reveal an instant or sorcery card with
converted mana cost less than or equal to the
number of magic counters on Mana Vortex.
Exile it. Until end of turn, you may cast the
instant or sorcery from exile without paying its
mana cost.