Oathsworn Knight is a rare Creature — Human Knight card from Throne of Eldraine (ELD), collector number 354. Current market price: $0.42 (foil $0.64), TCGplayer market prices via Scryfall.
This creature enters with four +1/+1 counters on it. This creature attacks each combat if able. If damage would be dealt to this creature while it has a +1/+1 counter on it, prevent that damage and remove a +1/+1 counter from it.