Abathur, the Researcher

{g}, Sacrifice another creature: Put a +1/+1
counter on target creature you control, then if it's
power is 6 or greater, draw a card. Activate only
as a sorcery and only once each turn.
{b}, Sacrifice another creature: Put a -1/-1
counter on target creature. Activate only as a
sorcery and only once each turn.
Whenever a creature dies, if it had a +1/+1 or a
-1/-1 counter on it draw a card. This ability
triggers only once each turn.