Saddana, the Mindstabber

Whenever an opponent reveals one or more cards,
you may choose a nonland card from the revealed
cards and pay life equal to its mana cost, if you do,
that player discards that card.
{1}{u}{b}: Until end of turn, when Saddana, the Mindstabber deals combat damage to an
opponent, that opponent reveals X cards at
random where X is equal to the damage dealt.