Fraudulent Negotiator

When Fraudulent Negotiator enters the battlefield, you and target opponent each reveal
the top 2 cards of your libraries. Exile one of
them face down, and put the rest on the bottom
their owner's library. You may look at and play
the exiled card for as long as it remains exiled,
and you may spend mana as though it were
mana of any color to cast that spell.