Soulcatcher

Death rewards an aggro creature, which is the structural oddity here: most growth payoffs ask for something proactive (deal combat damage, sacrifice fodder, cast spells), while this one feeds on attrition in the air. It scales off any flier dying anywhere, yours or theirs, so a board where birds and drakes trade in combat or get picked off by removal quietly inflates a one-power body into a real threat. That makes it strongest in a mirror of evasive creatures, the exact texture of a flier-heavy white deck, where every chump block and removal spell across the table is incidentally building your clock. The trigger keys on the flying keyword, not a creature type, so anything airborne that dies counts: this is a payoff for sky-control board states broadly, not a tribal commitment. The vulnerability runs the other direction, though. A single point of toughness means it arrives as a target rather than a threat, and it dies to the same removal that feeds it when that removal points elsewhere. The counters are real while the creature lives, but they have no permanence past it: a sweeper erases the growth outright, and bounce returns a blank slate with nothing banked from the work it did. Soulcatcher is built for a specific board state and contributes little outside it, but inside that board it turns combat losses into a win condition with unusual economy.