Flying Whenever Thief of Sanity deals combat damage to a player, look at the top three cards of that player's library, exile one of them face down, then put the rest into their graveyard. You may cast that card for as long as it remains exiled, and mana of any type can be spent to cast it.
Near Mint - $0.95
Lightly Played - $0.90
Moderately Played - $0.76
Heavily Played - $0.57
Damaged - $0.47
Near Mint Non-English - $0.95
Lightly Played Non-English - $0.90
Moderately Played Non-English - $0.76
Heavily Played Non-English - $0.57
Damaged Non-English - $0.47