Ida, of Immortal Treasures

Pay {x} mana and scry the top card from target
player's library. If the mana cost of the card is
less then the {x} mana spent and a creature, you
can cast it without paying for its mana cost.
You have control of it until the end of the turn,
however, if you can keep it on your side for
longer then a single turn, it becomes an
enchanted land permanently, that has {ut}, {c}.
It's the cost of out living them all.