Spooky Pact

Exile cards from the top of your library until you reveal 3 spooky cards with different names. An opponent of your choice separates those cards into two piles. You choose one of those piles. You may cast any number of cards from the chosen pile without paying their mana costs. Put any cards not cast this way on the bottom of your library.
At the beginning of your next upkeep, pay {1}{b}{b}. If you don't, you lose the game