Gonti, Lord of Luxury

Deathtouch
When Gonti, Lord of Luxury enters the
battlefield, look at the top four cards of target
opponent's library, exile one of them face down,
then put the rest on the bottom of that library
in a random order. You may look at a cast
that card for as long as it remains exiled, and
you may spend mana as though it were mana of
any type to cast that spell.