Knight Exemplar is a rare Creature — Human Knight card from Duel Decks: Knights vs. Dragons (DDG), collector number 14. Current market price: $5.55, TCGplayer market prices via Scryfall.
First strike (This creature deals combat damage before creatures without first strike.) Other Knight creatures you control get +1/+1 and have indestructible. (Damage and effects that say "destroy" don't destroy them.)