Brodi, Ruined King

When Brodi, Ruined King enters the battlefield,
look at the top card of each opponent's library,
exile one of them face down, then put the others
in their owner's graveyard. You may look at and
play that card for as long as you control Brodi,
and you may spend mana as though it were mana
of any type to cast that spell.
At the beginning of your end step, return Brodi
to its owner's hand, unless you return a land
card you control.