When Wightprincess enters the battlefield under your control, you can search your library for up to one Wightprince and send it to the graveyard. Your library is then shuffled.

{b}{b}{B/P}, {t}, sacrifice Wightprincess: target creature an opponent controls gains X -1/-1 counters, where X is its converted mana cost. Remove those counters placed by this ability during the end step of this turn.