Demetria, Harvester of Souls

Flying, Hexproof from white
{x}{x}{b/r}, {t}: Demetria deals X damage to any
target. When that target dies before your next
turn, create a food token and distribute two -1/-1
counters among one or two target creatures.
Whenever a player takes damage from Demetria,
note how much they have taken this game. If it's
16 points or more, they lose the game.