Brighthearth Banneret is a common Creature — Elemental Warrior card from Morningtide (MOR), collector number 88. Current market price: $2.41 (foil $21.66), TCGplayer market prices via Scryfall.
Elemental spells and Warrior spells you cast cost {1} less to cast. Reinforce 1—{1}{R} ({1}{R}, Discard this card: Put a +1/+1 counter on target creature.)