Long Zhi, the Fox

When Long Zhi, the Fox comes into play, and if opponent player controls at least one human creature, you may choose to pay {4}{w}. If you do,
exile cards from the top of your library until you
exile a nonland card whose converted mana cost
is less than or equals to this spell's converted
mana cost. You may cast that card without
paying its mana cost. Then put all cards exiled
this way that weren't cast on the bottom of your library in a random order.