Gix, Yawgmoth Praetor

Whenever a creature deals combat damage
to one of your opponents, its controller
may pay 1 life. If they do, they draw a card.
{4}{b}{b}{b}, Discard X cards: Exile the top X cards
of target opponent's library. You may play
lands and cast spells from among cards
exiled this way without paying their mana costs.
"All bonds are parasitic. Only rulership is pure."
—Gix