Dark Petition is a rare Sorcery card from Secret Lair Drop (SLD), collector number 2525. Current market price: — (foil $1.83), TCGplayer market prices via Scryfall.
Search your library for a card, put that card into your hand, then shuffle. Spell mastery — If there are two or more instant and/or sorcery cards in your graveyard, add {B}{B}{B}.