Thalor's Influence

When Thalor's Influence enters the battlefield put all creatures from all graveyards onto the battlefield under your control they become black zombie creatures in addition to thier other types.
All black creatures you control gain +1/+1 and all other cratures gain -1/-1.
Whenever a creature dies put it onto the battlefiel under your control it becoms a black zombie creature in addition to it's other types.