Ob Nixilis's Cruelty

Black shrink-effects have been trading one problem for another since the earliest days of the game: kill the aristocrats fodder and it feeds a death trigger, blast the persist body and it comes back a counter smaller. The exile rider on this one closes that loop. A -5/-5 at instant speed clears most of what a fair deck fields, but the replacement clause routes the death through exile whenever that creature would die this turn: no graveyard, no recursion, no reassembling a threat built to be sacrificed and rebought. That is the real design work, and it points the card squarely at the small, self-sacrificing creatures whose entire plan depends on hitting the yard. The price of that precision is the fixed number. -5/-5 is a hard toughness ceiling, and anything bigger simply walks through it, so this stays a scalpel rather than an unconditional answer. It does its cleanest work against the recursive, death-triggered engines that ordinary removal only accelerates, and against a genuine fatty it does nothing at all.