Mortal Sacrifice (Sacrifice any number of non-God, nonartifact creatures as you cast this spell to reduce its mana cost by their combined mana value.)

You may cast Aerecura, Harvester of Death from your graveyard or exile.

Flying

Whenever a mortal dies, exile it. If you do, you may put a +1/+1 counter or lifelink counter on a creature you control.