Breena, the Demagogue is a mythic Legendary Creature — Bird Warlock card from Commander 2021 (C21), collector number 328. Current market price: $22.71, TCGplayer market prices via Scryfall.
Flying Whenever a player attacks one of your opponents, if that opponent has more life than another of your opponents, that attacking player draws a card and you put two +1/+1 counters on a creature you control.