Heremod, Unfinished War

X equals to the number of spirit or zombie creatures in your graveyard.
Whenever Heremod, Unfinished War enters the battlefield or attacks, all spirit or zombie creatures you control gets a +1/+1 and return target spirit or zombie creature from a graveyard to the battlefield under your control.
"War will end, not till all is dead, not till one gains VICTORY"