Xiliantha, Madness Reincarnate

As an additional cost to cast this spell, discard
your hand and pay {3}{u}{b}{r}{g}.
You may cast spells from your graveyard.
As long as you have no cards in hand, whenever
you cast a spell, reveal cards from the top of your library until you reveal a nonland card that costs
more. You may cast it without paying its mana
cost. Then put the exiled cards on the bottom of
your library in a random order.