Inner Struggle

The clever trick here is turning a creature's own offense into the murder weapon. Most red removal scales the wrong way: a burn spell deals a fixed number, so it answers small threats and glances off the big ones. This inverts that curve. The bigger the attacker, the harder it hits itself, which makes it a clean answer to exactly the fatties ordinary red damage cannot reach. Instant speed lets it ambush during combat, pushing a defender into losing a fight it would have won on stats alone; the self-damage even piles onto any combat damage already marked that turn, since all damage on a creature accumulates until cleanup, so a body that has already blocked and taken a hit needs even less power to finish itself off. But the elegance has a floor built into the math: a zero-power creature deals zero, so the spell whiffs entirely against anything drained down to nothing, and it does nothing to trim a wide board because it is a four-mana single-target answer, not a sweeper. Because lethal damage destroys, it respects the usual escape hatches: an indestructible body shrugs it off, regeneration shields the target, and toughness boosts or damage prevention keep the creature alive by changing the equation it is being asked to solve. It belongs to the small family of red answers that make the target do the killing, treating raw power as a liability and a creature's own threat level as the lever that removes it.