Gravekeeper's Supernaturalist

2 "Gravekeeper's" monsters Gains ATK/DEF equal to the combined original Levels of the materials used for its Fusion Summon x 100. While "Necrovalley" is on the field, this card, and any card in your Field Zone, cannot be destroyed by card effects. During your Main Phase: You can activate this effect; during the End Phase of this turn, add 1 "Gravekeeper's" monster or 1 "Necrovalley" card from your Deck to your hand. You can only use this effect of "Gravekeeper's Supernaturalist" once per turn.