Seymour the Illusionist

Whenever another creature you control attacks,
each opponent reveals cards from the top of their library equal to the number of attacking creatures.
Choose a revealed card. Until the end of your
next turn, you may cast that card. Each opponent
then puts the revealed cards on the bottom of
their libraries.
"A one-eyed man is much more incomplete than a
blind man, for he knows what it is that's lacking."