Truefire Captain is a uncommon Creature — Human Knight card from Guilds of Ravnica (GRN), collector number 209. Current market price: $0.23 (foil $0.34), TCGplayer market prices via Scryfall.
Mentor (Whenever this creature attacks, put a +1/+1 counter on target attacking creature with lesser power.) Whenever this creature is dealt damage, it deals that much damage to target player.