Bringer of Languor

{u}, {t}, Discard a card: Counter target activated or triggered ability. (Mana abilities can't be targeted.)
{b}{b}, {t}, Discard a card: Target player discards two cards.
{1}{u}{b}, {t}, Discard a card: Target opponent reveals cards from the top of his or her library until four land cards are revealed. That player puts all cards revealed this way into his or her graveyard.