You can only cast this spell if both Necrovalley and a Gravekeeper Creature are on the battlefield under your control.

If a noncreature spell or an ability of a permanent on the field would put a creature or creature token onto the battlefield, counter it unless it is putting a Gravekeeper creature onto the battlefield faceup or facedown.

Exile this card if you do not control a Gravekeeper creature and/or Necrovalley.