The Meathook Massacre combines a scalable creature sweeper with a continuing payoff for creatures dying. When it enters, each creature gets -X/-X until end of turn. Afterward, the enchantment remains to make each opponent lose one life when your creatures die and gain you one life when an opponent’s creature dies.
Sacrifice decks can use a modest value of X to clear small opposing creatures while gaining value from their own expendable bodies. Because the enchantment is already on the battlefield when the entry effect resolves, its death abilities can trigger from creatures that die as a result. Casting it with X equal to zero is also an option when the ongoing death triggers are what the deck needs.
Ashnod’s Altar and Phyrexian Altar provide ways to sacrifice creatures at useful moments, turning your own deaths into mana and life loss for every opponent. Reassembling Skeleton or other recurring creatures can keep supplying material when the deck can pay their return costs. The enchantment does not create a loop by itself, but it gives a functioning sacrifice engine another way to finish the game.
The toughness reduction affects your creatures as well as opponents’, and larger values of X require substantial mana. It can remove indestructible creatures if their toughness reaches zero, but it does not exile graveyards or prevent death triggers. Decide how much of the board needs to disappear before choosing X. The strongest use leaves you with an enchantment that continues advancing your plan after the immediate reset has done its work.
