Sadistic Slash

A four-mana -5/-5 has been an unremarkable black rate since removal of this shape first appeared, and the base cost is priced to stay that way. Mayhem changes the accounting. The card is meant to be discarded as much as cast, splitting its real cost across two decisions rather than one. Pitch it to a rummaging effect, a looting outlet, or any of the discard triggers black leans on, and you can rebuy the -5/-5 for that same turn, converting a card you had already thrown away into a kill spell you still get to use. The one-turn window does the balancing work: Mayhem is not a graveyard toolbox you dip into whenever removal is needed, it is a single-turn conversion that only pays off if the discard and the recast line up. That timing pressure pushes the card toward decks already churning through their hands, where a card hitting the graveyard is a resource rather than a loss, instead of asking a deck to build around it from scratch. Both casts happen at instant speed, so the recast still respects the same combat and stack windows the hardcast would, provided you spend the mana before the turn ends. It is a modest kill spell bolted to a mechanic that pays you for the thing most black decks treat as pure cost.