Malves, The Dark Arisen

{u}{u}{t}: Tap target creature then put a void
counter on that creature. It doesn't untap
during it's controller's next upkeep.
{b}{ut}: Each creature with a void counter takes 2
damage then you draw X cards where X is the
number of void counters in play.
Malves, The Dark Arisen's power is equal to the
number of void counters in play