Planar Graft

Exile the top four cards of target opponent's library face down. For as long as those cards remain in exile you may look at them, cast them
as though they had flash and spend mana as if it were mana of any color to cast them.
Contingency If you would exile a land, you may instead play a card without paying its mana cost.
If you do, put the remaining three cards into two piles face down. Your opponent chooses one to put in their hand and one into their graveyard.