Impatient Sphinx

Flying, vigilance, haste
Sadness {p/b}{p/g}{p/r}{p/w} (If you would exile this from anywhere, you may cast it for its sadness cost instead.)
{p/u}{p/u}: Shuffle Impatient Sphinx into its owner's library. Then, each player exiles the top four cards of their library. Then, its owner may search their library for a card named Impatient Sphinx, reveal it, put it into their hand, and shuffle. Anyone may activate.