When the effect of "Necrovalley" is applying, you cannot Special Summon a "Hieratic" Normal Monster from the Graveyard with the effect of "Hieratic Dragon of Gebeb", etc. Therefore, when the effect of "Necrovalley" is applying, you can only Special Summon a "Hieratic" Normal Monster with the effect of "Hieratic Dragon of Gebeb", etc, from the hand or Deck.[7]
↑Konami OCG FAQ: When is the ATK and DEF of a Dragon-Type Normal Monster Summoned from the hand/Deck/Graveyard by the effect of "Hieratic Dragon of Gebeb" reduced to 0?
↑Konami OCG Card Database: If "Hieratic Dragon of Gebeb", etc, is Tributed while "Necrovalley" is applying, can you Special Summon from the Graveyard?