Underworld Fires

A single point of damage is usually filler in red's sweeper slot: cheap enough to clear a board of 1/1s, weak enough to leave everything larger standing. The exile rider is what changes the job. Only the creatures and planeswalkers this spell actually damages get the replacement effect, so the clause is a leash on the sweep itself: anything it touches that dies this turn (whether from these fires alone or from combat and a follow-up burn spell stacking on top of the same point) leaves the game rather than the graveyard. That distinction is the entire pitch against aristocrats and reanimator strategies. The replacement is total: a creature that would die from the damage never actually dies, so it not only fails to reach the graveyard as reanimator fuel, it never fires the death triggers a sacrifice deck was counting on. The permanent simply exits, no last value on the way out. The planeswalker line does the same work: shave a point of loyalty, and a walker that falls under the effect this turn is exiled rather than left to be milled back or recurred. The tension is in the tuning. One damage rarely finishes a durable board on its own, so the exile only bites when the small ping combines with combat or a second spell to actually reduce something it damaged to zero. That narrow window is deliberate: it turns a low-impact clear into a hard answer aimed precisely at decks that treat their creatures' deaths as an asset.