Trixy, Court Jester

When Trixy, Court Jester enters the battlefield,
an opponent chosen at random becomes the
monarch.
Whenever an opponent draws a card for being the monarch, look at the top 4 cards of that player's library. Exile 1 of them face down, then put the
rest on the bottom of that library in any order. You
may look at and 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.