Marchesa's Infiltrator is a uncommon Creature — Human Rogue card from Conspiracy (CNS), collector number 22. Current market price: $0.22 (foil $0.54), TCGplayer market prices via Scryfall.
Dethrone (Whenever this creature attacks the player with the most life or tied for most life, put a +1/+1 counter on it.) Whenever this creature deals combat damage to a player, draw a card.