You can only control 1 face-up "Gravekeeper's Chief". Cards in your Graveyard is unaffected by "Necrovalley". When this card is Tribute Summoned, you can Special Summon 1 "Gravekeeper's" monster in your Graveyard.
Near Mint Unlimited - $0.50
Lightly Played Unlimited - $0.48
Moderately Played Unlimited - $0.41
Heavily Played Unlimited - $0.36
Damaged Unlimited - $0.26