Duskmantle Spymaster

{t}: Put the top card of target player's library into their graveyard.
Transmute instant {1}{u/b}{u/b} ({1}{u/b}{u/b}, Discard this card: Search your library for an instant card with the same converted mana cost as this card, reveal it, and put it into your hand. Then shuffle your library. Transmute only as a sorcery.)