Circle of Protection: Black [International Collectors' Edition] 56 while both have "Gravekeeper's" monster

while both have "Gravekeeper's" monster and "Necrovalley" are on the field: Negate the activation

Set: Khans of Tarkir Type: Creature — Human Warrior Rarity: Rare Cost: {B} Bloodsoaked Champion can't block

also all WATER monsters on the field lose 400 ATK/DEF

Set: Lightning Overdrive Card type: Effect Monster Rarity: Secret Rare Attack: 1100 Defense: 1900 Once per turn

Circle of Protection: Black [International Collectors' Edition] 56 while both have "Gravekeeper's" monsterSet: International Collectors' Edition Type: Enchantment Rarity: Common Cost: {1}{W} {1}: The next time a black source of your choice would deal damage to you this turn, prevent that damage.