Knights of the Black Rose is a uncommon Creature — Human Knight card from Conspiracy: Take the Crown (CN2), collector number 76. Current market price: $0.30 (foil $1.31), TCGplayer market prices via Scryfall.
When this creature enters, you become the monarch. Whenever an opponent becomes the monarch, if you were the monarch as the turn began, that player loses 2 life and you gain 2 life.