Selfless Squire is a rare Creature — Human Soldier card from Murders at Karlov Manor Commander (MKC), collector number 82. Current market price: $0.39, TCGplayer market prices via Scryfall.
Flash When this creature enters, prevent all damage that would be dealt to you this turn. Whenever damage that would be dealt to you is prevented, put that many +1/+1 counters on this creature.