Jiang Yanggu, Alone is a uncommon Legendary Creature — Human Berserker card from Reality Fracture (FRA), collector number 246. Current market price: $0.24 (foil $0.18), TCGplayer market prices via Scryfall.
Menace (This creature can't be blocked except by two or more creatures.) Whenever a creature you control attacks a player alone, discard a card, then draw a card. Then put a +1/+1 counter on that creature for each card you've discarded this turn.