Vonclir, Kirakin's Heir

Flash
When Vonclir, Kirakin's Heir enters the battlefield, target opponent sacrifices two
attacking creatures he controls and you gain 3 life.
{1}{b}{g}, Sacrifice a creature: Put a +1/+1 counter
on target creature, a -1/-1 counter on target
creature and return Vonclir, Kirakin's Heir to
your hand.