Spiteful Banditry

Red rarely gets to sweep the board on its own terms, and almost never gets to bank the reward. Scaling damage to each creature is old territory for white and black, the plague effects and the pyroclasms grown up into wraths, but stapling a repeatable Treasure engine to the aftermath is what reframes what a red sweeper is for. The X-damage entry is the tempo swing; the death trigger is what turns a defensive reset into an offensive resource. Once it resolves, every turn an opponent's creature dies refills your mana, so the card keeps paying rent long after the initial wipe has stopped mattering. Restricting the Treasure ability to a single trigger per turn is the honest limiter: a mass death does not cascade into an unbounded pile of tokens, so the value accrues one Treasure at a time rather than snowballing off one board-clearing turn. That makes it a slower engine than it first reads, which is precisely what keeps a permanent Treasure generator from being oppressive. Red wants to trade one-for-many and then keep the initiative, but sweepers historically leave the caster tapped out and empty-handed; this answers both in a single enchantment that stays on the battlefield to keep answering them, an unusual persistence for a color that usually spends its resources the moment it draws them.